If your idle speed is 1000 rpm and start stop doesn't activate that's a pretty good indicator of a regen....
FI don't disagree with what you are saying. I doubt however much lobbying was done it wouldn't have been successful.
I would have thought, just a light on when doing a regen so you know not to stop would solve the issue. I also don't understand if it was so simple why lots of manufacturers are having the same issues, not just VW. I just try to look at the rev counter before switching off to see if its mid regen or not and dont switch off if it is, I try to drive a bit further if it is possible.
I believe that someone on here has retrofitted a light to indicate regen in process.
I have never seen or heard of a Transporter with that button. Never seen it mentioned anywhere before, which is strange, and make me doubt the dealer.