Ok, this is not perfect yet, but this is production firmware 19.8.3 and it does a lot of new tricks.
Obviously you cannot yet enable it in GUI, and for a good reason that I'll list below.
It can also stop for stop signs but I cannot find a good location to video it without putting anyone in danger so that's for another time.
nice touch - if it is unsure of current light status - it would approach the intersection carfully so it can stop gently should it actually be a red light - see at 6:26
So now the problems. it's actually not very robust at telling red from green in some conditions, see at timestamp 4:05 how it flipflops. and then nearly runs a red light at 5:12 and I need to intervene.
Overall I am very impressed.