I'm not quite sure if you're describing the problem or the solution?
If it's a solution, I'd like to know more, to see if it's something I could recommend to people that are likely to encounter the regen-vs-bms-shutdown issue.
(we get them every so often, especially those that need to start their whole journey from the top of a hill and want to use regen to slow their descent but also start with a full or near-full battery).
For your people starting at the top of a hill and running regen, the solution is simple: just set the over voltage fault significantly below the DCDC/MOS/caps rating, and it will be OK unless you are running into field weakening on your hill
If you are field weakening, find the motor max speed WITHOUT the FW enabled, and set that as an rpm limit, or scale the max speed linearly with the voltage margin available... this forces the controller to stay at a safe speed.
At the end of the day, if you hang on to a car and get towed to 50mph over your base speed, your controller is going to die regardless. There comes a point when common sense and correct system specification is important.
Automotive can implement a number of solutions, including not shutting off the battery, pre-emptively rolling back power, forcing use of the main brakes, running at reduced power factor to waste energy into the motor... etc... but this takes substantial system design, analysis and testing, way beyond the willingness of the average builder.
For about 3 years now, VESC has behaved well with regards to over voltage protection, shutting down very rapidly in the event of an over voltage fault. Everything still needs analysing critically from a system design perspective with failure modes in mind, there is no one component that can solve your issue.
www.vesclabs.com
