diff --git a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/deviceattributes.js b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/deviceattributes.js
index 9e097ad84..7df9dca9d 100644
--- a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/deviceattributes.js
+++ b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/deviceattributes.js
@@ -48,7 +48,7 @@ export default {
     parameters: (itemType, item) => [
       p.inverted(itemType === 'Rollershutter'),
       p.presets(item.stateDescription, '20=Morning,60=Afternoon,80=Evening:@Setting.Night'),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       p.actionMappings({ default: 'value' }, 'Close=0,Open=100,Lower=0,Raise=100', (config) => {
         const primaryControl = getGroupParameter('primaryControl', item.groups) || 'position'
         if (itemType === 'Dimmer') {
@@ -73,7 +73,7 @@ export default {
     parameters: (itemType, item) => [
       p.inverted(itemType === 'Rollershutter'),
       p.presets(item.stateDescription, '20=Morning,60=Afternoon,80=Evening:@Setting.Night'),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       ...(getGroupParameter('primaryControl', item.groups) !== 'tilt' ? [] : [
         p.actionMappings({ default: 'value' }, 'Close=0,Open=100', (config) => {
           if (itemType === 'Dimmer') {
@@ -107,7 +107,7 @@ export default {
     itemTypes: ['Number', 'String'],
     parameters: (itemType, item) => [
       p.supportedInputs(item.stateDescription, itemType === 'String' ? 'HDMI1=Cable,HDMI2=Kodi' : '1=Cable,2=Kodi'),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       p.retrievable()
     ]
   },
@@ -410,7 +410,7 @@ export default {
       p.retrievable(),
       p.supportedModes(item.stateDescription),
       p.ordered(),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       p.actionMappings(
         { set: 'mode', ...(config.ordered && { adjust: '(±deltaValue)' }) },
         'Close=Down,Open=Up,Lower=Down,Raise=Up'
@@ -421,7 +421,7 @@ export default {
   RangeValue: {
     itemTypes: ['Dimmer', 'Number', 'Number:*', 'Rollershutter'],
     supports: ['multiInstance'],
-    parameters: (itemType, item) => [
+    parameters: (itemType, item, config) => [
       p.capabilityNames(item.groups.length ? item.label : '@Setting.RangeValue', '@Setting.FanSpeed,Speed'),
       p.inverted(itemType === 'Rollershutter'),
       p.nonControllable(item.stateDescription),
@@ -432,12 +432,17 @@ export default {
           ? [p.supportedCommands(['UP', 'DOWN', 'MOVE', 'STOP'], 'UP=@Value.Open,DOWN=@Value.Close,STOP=@Value.Stop')]
           : []),
       p.supportedRange(
-        item.stateDescription,
-        itemType === 'Dimmer' || itemType === 'Rollershutter' ? '0:100:1' : '0:10:1'
+        item,
+        config,
+        itemType === 'Dimmer' || itemType === 'Rollershutter'
+          ? '0:100:1'
+          : config.nonControllable
+            ? '0:10:0.01'
+            : '0:10:1'
       ),
       p.presets(item.stateDescription, '1=@Value.Low:Lowest,10=@Value.High:Highest'),
       p.unitOfMeasure(item),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       p.actionMappings({ set: 'value', adjust: '(±deltaValue)' }, 'Close=0,Open=100,Lower=(-10),Raise=(+10)'),
       p.stateMappings({ default: 'value', range: 'minValue:maxValue' }, 'Closed=0,Open=1:100')
     ]
@@ -452,7 +457,7 @@ export default {
         : [p.inverted()]),
       p.nonControllable(item.stateDescription),
       p.retrievable(),
-      p.language(item.settings && item.settings.regional.language),
+      p.language(item.settings?.regional?.language),
       p.actionMappings(['ON', 'OFF'], 'Close=OFF,Open=ON'),
       p.stateMappings(['ON', 'OFF'], 'Closed=OFF,Open=ON')
     ]
diff --git a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/devicetypes.js b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/devicetypes.js
index 8bd93d8a8..1f93bcb1b 100644
--- a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/devicetypes.js
+++ b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/devicetypes.js
@@ -60,7 +60,7 @@ const thermostatAttributes = [
 
 const blindParameters = (_, item) => {
   const attributes = ['PositionState', 'TiltAngle']
-  const metadata = item.members.map((mbr) => mbr.metadata && mbr.metadata.alexa.value).join(',')
+  const metadata = item.members.map((mbr) => mbr.metadata?.alexa?.value).filter(Boolean).join(',')
   return attributes.every((attr) => metadata.includes(attr)) ? [p.primaryControl()] : []
 }
 
diff --git a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/helpers.js b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/helpers.js
index 1a69d77cc..119e3d865 100644
--- a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/helpers.js
+++ b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/helpers.js
@@ -19,7 +19,7 @@ export const docLink = (title, anchor) => {
   return `<a class="external text-color-blue" target="_blank" href="${link}">${title}</a>`
 }
 
-export const getGroupParameter = (parameter, groups) => {
+export const getGroupParameter = (parameter, groups = []) => {
   for (const group of groups) {
     const config = group.metadata.alexa.config || {}
     if (parameter in config) return config[parameter]
@@ -39,25 +39,34 @@ export const getSemanticFormat = (type, format) =>
     ''
   )
 
+export const getSupportedRange = (item, config, defaultValue) => {
+  const { minimum, maximum, step, pattern } = item.stateDescription || {}
+  if (!isNaN(minimum) && !isNaN(maximum) && !isNaN(step)) return `${minimum}:${maximum}:${step}`
+  const itemType = item.groupType || item.type
+  if (itemType.startsWith('Number') && config.nonControllable) {
+    const { precision, specifier } = pattern?.match(/%\d*(?:\.(?<precision>\d+))?(?<specifier>[df])/)?.groups || {}
+    const [minimum, maximum] = defaultValue.split(':', 2)
+    if (specifier === 'd') return `${minimum}:${maximum}:1`
+    if (precision <= 16) return `${minimum}:${maximum}:${1 / 10 ** precision}`
+  }
+  return defaultValue
+}
+
 export const getTemperatureScale = (item) => {
   const itemType = item.groupType || item.type
-  const unitSymbol = item.unitSymbol
-  const statePresentation = (item.stateDescription && item.stateDescription.pattern) || ''
-  const format = (itemType === 'Number:Temperature' && unitSymbol) || statePresentation
-  if (format.endsWith('°C')) return 'CELSIUS'
-  if (format.endsWith('°F')) return 'FAHRENHEIT'
-  const { measurementSystem } = (item.settings && item.settings.regional) || {}
+  const format = (itemType === 'Number:Temperature' && item.unitSymbol) || item.stateDescription?.pattern
+  if (format?.endsWith('°C')) return 'CELSIUS'
+  if (format?.endsWith('°F')) return 'FAHRENHEIT'
+  const measurementSystem = item.settings?.regional?.measurementSystem
   if (measurementSystem === 'SI') return 'CELSIUS'
   if (measurementSystem === 'US') return 'FAHRENHEIT'
 }
 
 export const getUnitOfMeasure = (item) => {
   const itemType = item.groupType || item.type
-  const unitSymbol = item.unitSymbol
-  const statePresentation = (item.stateDescription && item.stateDescription.pattern) || ''
   const format =
     ((itemType === 'Dimmer' || itemType === 'Rollershutter') && '%') ||
-    (itemType.startsWith('Number:') && unitSymbol) ||
-    statePresentation
-  return Object.keys(UNITS_OF_MEASURE).find((id) => format.endsWith(UNITS_OF_MEASURE[id]))
+    (itemType.startsWith('Number:') && item.unitSymbol) ||
+    item.stateDescription?.pattern
+  return Object.keys(UNITS_OF_MEASURE).find((id) => format?.endsWith(UNITS_OF_MEASURE[id]))
 }
diff --git a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/parameters.js b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/parameters.js
index cfbfe10b0..5153406f1 100644
--- a/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/parameters.js
+++ b/bundles/org.openhab.ui/web/src/assets/definitions/metadata/alexa/parameters.js
@@ -13,6 +13,7 @@ import {
   getGroupParameter,
   getOptions,
   getSemanticFormat,
+  getSupportedRange,
   getTemperatureScale,
   getUnitOfMeasure,
   titleCase
@@ -202,7 +203,7 @@ export default {
     name: 'nonControllable',
     label: 'Non-Controllable',
     type: 'BOOLEAN',
-    default: (stateDescription && stateDescription.readOnly) === true,
+    default: stateDescription?.readOnly === true,
     visible: (_, config) => !!config.retrievable
   }),
   ordered: () => ({
@@ -229,14 +230,12 @@ export default {
       ` (${docLink('Asset Catalog')})`,
     type: 'TEXT',
     default:
-      stateDescription &&
-      stateDescription.options &&
-      stateDescription.options
-        .filter((option) => !isNaN(option.value))
+      stateDescription?.options?.filter((option) => !isNaN(option.value))
         .map((option) => `${option.value}=${option.label}`)
         .slice(0, STATE_DESCRIPTION_OPTIONS_LIMIT),
     placeholder: placeholder.replace(/,/g, '\n'),
-    multiple: true
+    multiple: true,
+    visible: (_, config) => !config.nonControllable
   }),
   primaryControl: () => ({
     name: 'primaryControl',
@@ -356,10 +355,7 @@ export default {
     description: 'Each input formatted as <code>inputValue=inputName1:inputName2:...</code>',
     type: 'TEXT',
     default:
-      stateDescription &&
-      stateDescription.options &&
-      stateDescription.options
-        .map((option) => `${option.value}=${option.label}`)
+      stateDescription?.options?.map((option) => `${option.value}=${option.label}`)
         .slice(0, STATE_DESCRIPTION_OPTIONS_LIMIT),
     placeholder: placeholder.replace(/,/g, '\n'),
     multiple: true,
@@ -372,10 +368,7 @@ export default {
       `Each mode formatted as <code>mode=@assetIdOrName1:@assetIdOrName2:...</code> (${docLink('Asset Catalog')})`,
     type: 'TEXT',
     default:
-      stateDescription &&
-      stateDescription.options &&
-      stateDescription.options
-        .map((option) => `${option.value}=${option.label}`)
+      stateDescription?.options?.map((option) => `${option.value}=${option.label}`)
         .slice(0, STATE_DESCRIPTION_OPTIONS_LIMIT),
     placeholder: 'Normal=Normal:Cottons\nWhites=Whites',
     multiple: true,
@@ -391,18 +384,12 @@ export default {
     multiple: true,
     advanced: true
   }),
-  supportedRange: (stateDescription, defaultValue) => ({
+  supportedRange: (item, config, defaultValue) => ({
     name: 'supportedRange',
     label: 'Supported Range',
     description: 'Formatted as <code>minValue:maxValue:precision</code>',
     type: 'TEXT',
-    default:
-      stateDescription &&
-      !isNaN(stateDescription.minimum) &&
-      !isNaN(stateDescription.maximum) &&
-      !isNaN(stateDescription.step)
-        ? `${stateDescription.minimum}:${stateDescription.maximum}:${stateDescription.step}`
-        : defaultValue,
+    default: getSupportedRange(item, config, defaultValue),
     pattern: '[+-]?[0-9]+:[+-]?[0-9]+:[0-9]+'
   }),
   supportedThermostatModes: () => ({