Large and scalable heated Bed

good morning to every body,
I have this idea from a couple of weeks and I want to discuss with you the feasibility.
My idea is simple:
-to male a large heated bed using 4 heated bed MK2 2x2.
Plus I want also give an independent regulation for each H.B. with an independent temperature feedback (1° from the original 2°-3°-4° an external power section controlled by the I/O of the RAMPS 1.4).
So if I need to print a small piece I will enable only 1 H.B. or 2 if it is large, ext.
Now I'm planning the PCB.
I like to have your opinion on how can be useful, and also what can be the problematic to print on a big area
bye bye

This has been done...

You will need a alu heat spreader over the heaters, to over come the cold edges of the HBPs in the middle joins.

This will require at 4 * 11amps, 44amp at 12v, is not to be taken lightly.

I know the person who did this quickly changed his mind and went with a mains powered large silicon heater, also removes the need to have a heat spreader. but lots the ability to only heat sections.

All large printers need to be enclosed in a temperature controlled environment...