It’s not in either 2023 model year vehicle I own, but I have seen it on full time in another. But I have never seen it active below speeds of about 35mph (i.e. most city driving)

Interesting; when did this happen? From my experience, ~2017-era cars had it only as part of cruise control.

Keeping it on at all times sounds like a terrible idea for cars used in the US, because it's a developing nation with extremely poor road quality. In developed nations, it's probably OK because you can count on the road markings being good almost everywhere, but not in the US.

I think it only turns on above certain speed and yes, it can get easily confused by various road imperfections.

But yeah, you need to make sure there is a physical button on the steering wheel or somehere on the dashboard to easily enable/disable it. Otherwise it can be annoying.