I'm not an electronics connaisseur but can the seats just operate with simple 12V power and get rid of the ECU also? I mean all they do is go front and back? Or is that gonna mess other things up like the windows and handbrake?
There is no necessity to keep the ECU there, but keeping the wiring there and adding seat power relays there would save a lot of rewiring. The windows operate independently of the Roof ECU. You would just have to make sure the microswitch switch at the bottom of the left hand ram remained open circuit as this interferes with window manual operation (when the roof is unlatched from the windshield top frame).
As far as I know, the handbrake wiring runs in parallel with the roof circuit, so I don't foresee see any problems with that (as long as you don't delete the wiring splices by mistake).
To me the way the top came from the factory is just ridiculous...the whole sequence thing is just flat out dumb...especially if you are in a rush because it started raining or it became blistering hot, etc...all it does is piss ya off...and it's embarrassing...I literally cannot wait to just unlatch at the windshield and drop it back like my kid's Miata...zero drama and super fast...My car is at the Ferrari shop and they are doing the conversion shortly : )
Do you have any details on what they intend to do? i.e. remove the Roof ECU and install separate relays for the seats? I'd also be curious to know (after their mod) if the windows still drop 2 inches when the roof is unlatched. If you forget to drop the windows manually (if required), you may damage the glass.
My 355 has been converted in the past, with a 348 roof with steel connecting bar over the bulkhead, and 348 manual spider seats without the heavy machinery underneath. Now everything is manual: top, seats, and no microswitches or hydraulic lines or motors.. But the 348 top still is not as easy as a miata, or like the TVR Chimaera that I have: those you simply throw back. The 348 top needs to be folded partly by a lever, still a very strange hinged system. Apart from some leather interior parts, the serious hardware had been removed as well. It was like this when I bought it. At first I had planned to restore back to hydraulics, but when I found out what was missing on components, I quickly discarded that option. I know that it hurts the value , but it is, what it is. Now I only drive when it is dry anyway, so the top is always down.