The phone app does not use the V1 API and hasn't for a long time, so I don't quite follow the reasoning that a change to the V1 API would be related...
Did anybody from this or the Domoticz community ever succeed in getting an official appID from Honeywell? Or are we still collectively relying on one...
Well one day I came home (later than my other half) and found the DTS92 that normally sits on one of the loudspeakers in the living room disassembled...
Personally I don't think a DTS92 will solve your problem, if one end of the room is always colder than the other due to it being so long and one end...