yes you could fit it in the loft but the bath would be better if possible.
Whats the difference between fitting in the loft and fitting under the bath ?
Distance, the closer the tap the better, remember the tap will still let by up to the check valve, you could in practice find that the cold pressure will stop the hot flow completely if its too far away
So finally then , before I dismantle the bath panel , based on all the information , photos and tests that have been carried out over the last week , are we 100% certain that fitting an NRV to the hot feed of the mixer tap on the bath will sort my problem ?
It cant be any blockage , a faulty boiler or themostat elsewhere in the house ?
Also , if I fit an NRV , as required , can i expect to notice any difference to the water flow released from the bath tap ?