Every FSD Beta video I watch shows the system no longer in the FSD beta mode when they get on the highway.
My assumption is they are different modules.
It's possible that the highway module gets better too but not because you got the latest FSD beta. That means you don't need the latest FSD beta to see better skills on highways. And that means if non-FSD-Beta people like us got an improved highway skill, FSD Beta people will get it too.
Some say that is not true. FSD beta means new city streets AND highway competencies too. They reason that the user interface may look the same on highways but the codes and the skills are definitely FSD beta and not away as inferior as just plain public released FSD. I doubt that is true because there's no evidence that FSD beta can reliably avoid collisions unless humans do it for them.
Unless some computer programmer is willing to share the secret, your guess is just as good as mine.
I don't know about all of you but in my experience highway driving is far from perfect with the latest version of EAP - the most scary of which is stationary objects and how it handles construction.
It's possible that you have not experienced a stationary object scenario and constructions until now and that make you think the new version is worse.
It has been like that since 2014 AP1 and that's why there have been Autopilot collisions and fatalities.
To fix those problems above, Elon Musk will soon discontinue RADAR and go visual only.
Other non-Tesla like Waymo have proven that you can solve those above problems by adding LIDAR.
Until that will happen, I don't think those above problems will be solved for Tesla at any time soon.
Sure, Tesla will solve that with visuals if you give it some time ("soon"). But will we be still alive to see the result is another issue!