I hear what you're saying but I just don't get it, sorry.
I love the Fiat coupé but for me it's an IC car, not an EV. It is a car of it's time, and if the future, probably well beyond me, dictates that IC must die then sadly I must say RIP to the Coupé
For me any EV chassis needs to have low down weight, with the cells inside the wheelbase. Trying to achieve that in a chassis designed for IC is just far too compromised, too much weight for a start. This can be seen in many early EV attempts by regular vehicle manufacturers. Those attempts have poor range, poor efficiency and insufficient tech management for the cell packs. If I absolutely had to build an EV kit then it would be on a bespoke chassis clad in some lightweight panels - a sort of Lotus 7 / Elise kind of thing.
I do sadly suspect the EV modification route won't be tolerated for long though. Videos and TV shows demonstrating super fast VW Beetles, Minis & Campervans will soon have legislators picking up on the lack of NCAP safety standards of these OLD vehicles, both for occupants and other road users. The EV conversion market could soon become a victim of its own success.
It does appear that manufacturers could offer EV sports cars in the future, so the future may not be bleak.