Note that Map updates which might happen overnight without seeing or ok’ing install might have improved some situations.My 2018 the same with Beta. So much improved even over the past couple of months. Improvements happen even without getting an update, from what I experience. Highway lane merges are big hard arresting brakes though. Initiating changing of lanes/merging by braking is a nuisance that they haven't corrected yet. Just tapping on the 'gas' for a bit makes Beta/NOA change lanes way easier. Beta also still finds ways to stop hard in middles of intersections that are too closely spaced. But the overpass/shadow/big truck braking for me is substantially reduced. I don't think my issues I have today are 'lack of radar' based. Love the progress and it'll be excruciating to drive like grandma again after I get MXP.
But tapping throttle does not teach the car to handle locations better. It used to be very inconsistent. These days you can typically see why it brakes. Usually merges. Shadows, bridges, Sun have very little impact these days. And your foot didn’t teach it that.
I could also tell it appears to download maps as you go. I think my car recently update to new maps. Driving to a new area I’ve not driven before. Map updating was awful. No street names, no POI’s very course and chunky. I even tried rebooting. Next day I took the same route and it was perfect. It downloaded some stuff as needed. It may download meta data like speeds. Etc. more dynamically as well.