Moving the room stat out of the lounge will not fix the problem, the lounge will still be hot when the other rooms are warm. If there is no problem with the systems flow and it is balanced correctly there is a system design fault, either lounge radiators are over sized or other rooms are under sized. Trvs give the occupier the capacity to have rooms colder than the room stat setting, or easily turn rads off, up or down. Unfortunately many installers put any size rad in put a TRV on it and think that's system design.