I think it would be cool if Main UI could display an additional message flag about the status of things while online for example like the one below.

I was thinking of using the combination ThingStatus.ONLINE + ThingStatusDetail("Message") where Message is any (short) text about the status of the Thing e.g. "Update Avail" / "Low Batt" ..

Obviously it would require changes in OH-Core and OH-WebUI since the combination of ThingStatus.ONLINE + ThingStatusDetail is currently not allowed. => WDYT?

EDIT:

Interestingly the statusInfo.description text is already available via Rest API .. so perhaps we only need to implement that in the web UI. There are only 25 addons that currently set "status": "ONLINE", "statusDetail": "NONE", "description": "something". And it is not evident that such text ever appears anywhere except via the Rest API. So we could probably use this text in Main UI without changing anything in code. Although we might have to look at those 25 addons to make sure the text is not too long.

{
  "channels": [],
  "statusInfo": {
    "status": "ONLINE",
    "statusDetail": "NONE",
    "description": "cloud server responded"
  },
  "editable": false,
  "label": "Siemens Cloud Server",
  "configuration": {
    "pollingInterval": 60,
    ...
  },
  "properties": {
    "modelId": "ClimatixIC",
    "vendor": "Siemens"
  },
  "UID": "siemensrds:climatixic:cloud",
  "thingTypeUID": "siemensrds:climatixic",
  "location": "Home"
}

we might have to look at those 25 addons to make sure the text is not too long

Oops. Here is one such ...

  "statusInfo": {
    "status": "ONLINE",
    "statusDetail": "NONE",
    "description": "There are more than one bridges defined. This is of course possible with several Velux KLF200 gateways or with a redundant setup (SLIP via LAN parallel to JSON via WLAN). Every other case should be avoided."
  },