FWIW, these programs behave differently for reasons .. otherwise there would be a need for just one of them.
They do seem to be getting more and more cross-merged and integrated, but sometimes RB does what it does because that is the functionality most users expect and want. First thing I do when opening a BiaB file in RB is 'Make all BB tracks regular tracks'. If I went the other way I would expect some caveats .. RB handles tracks, routing, etc. much differently that BiaB

I personally cannot see why anyone would want to go the other way, and thus I assume it is a small group that would .. so I'm biased.
It would feel like I went backwards.
A couple others have mentioned the same (BB -> RB -> DAW workflow) so I'm not alone here.

Make your sound your own!
.. I do not work here, but the benefits are still awesome