Attacking the nause from a different direction, consider putting in some coilovers (Unplugged Performance, Mountain Pass Performance or Redwood Motorsports) comfort/GT etc to improve the suspension feel. It might set you back $3k to $5k but should be worth it. But as others say, just don't release the accelerator pedal, let up on it more gently. Get a feel for how fast total release of it is vs letting up on it slowly.
Changing the suspension isnt going to change the fact that it appears the OP, by their own words in this thread, has not learned how to modulate the pedal for regen braking. They also are not interested in changing how they drive, either, again by their own words in this thread.
I doubt the low regen setting is coming back for those cars that dont have it. We dont know for sure, but when it was changed, there was a lot of speculation that it was due to how government regulation tends to work on stuff like this.
What I mean is, if they are using "XXX amount of regen as energy into the battery as algorithm for battery range", but there is an easy toggle switch to turn that regen down, the government would make them use that low setting in all calculations for reported range.
Similar things happen in ICE vehicle land with things like the engine automatically stopping and then re starting every time you come to a stop. My BMWs had that feature (and it was horrible, I hated the engine always stopping in my ICE vehicle at a light, it was panic inducing). They originally had an in car setting where you could defeat it permanently, then they took that away and made it so you had to turn it off every single drive.
It was supposed to save 10% gas usage thus increase the MPG that BMW was quoting. If it was easily defeatable by the owner, BMW couldnt use it to increase the MPG, so they removed the ability to easily defeat it. You had to code it off using software designed for the service technicians to access the vehicle.
There was speculation that regen setting in teslas was a similar situation.
In any case, its been a while since they changed it, so its not likely coming back. OPs choice is go either learn how to drive more smoothly, live with their family complaining, use some sort of third party tool which allows changing this, or sell and find a car which allows them to defeat it.
Driving with smooth regen in these cars is not hard, at least in my opinion, but the OP specifically stated they were not interested in that.