In case this is important, i use
I use HA to switch my boiler on/off regarding heating need, but i use my own calculation for it. It switches on if a used room needs heat, but not immediately if a room on eco wants heat and it takes into account the TRV valves percent.
So the TRV state is no sign of really heating if the boiler is off.
Regarding flow loss, i thinnk its also the 3 rooms between boiler and living room which use up the heat, if there TRVs are open.