The car is indeed what I thought it would be for €200.

If I get on-board, I'll convert my current ICE, so I don't have to pinch my nose.

And I'll increase the budget to €2000.
I've seen your video in which you present the 600A/600V IGBTs.
I guess you'll be changing direction electronically with the full IGBT bridge, the low side on/off (the new TH driver board) and PWM on the high side.
How about two MOSFETs and two schottky diodes? MOSFETs on the high side, diodes in the low side leg. Unidirectional. Any chance that such a setup is compatible with the REVOLT and your ideas?
For driving in reverse I'll use the existing gearbox. Is it possible that the switch for the reversing light on the gearbox puts the controller in low torque mode?