Thanks for your replies:
@skywatch: yes I considered it infact I would leave some space for insulating material between the radiator and the installation. Also printing in ABS is a solution if warping issue is managed properly.
zboblamont: thanks for your advices. Nevertheless this system would be on top of all the insulation works and the increase of overall efficency level. The fact is purely that you don't want a big house to be always fully warmed, but you want a schedule to change temperature throughout day/night according to your presence in the house. Thermostatic valves have the downside of setting the temperature at the radiator head but not being able to be changed from remote. Unless there are valves that can do that with H.A. but so far I am not aware of any with this feature...