<<< Well, I figured out how to convert BB tracks to RB tracks. >>> and <<< Next, I tried to re-generate all the tracks again as RB tracks, but RB said that "there are no previously generated tracks found to re-generate." >>> plus

You are correct that generation of tracks is a BIAB function within RealBand. The message you saw is telling you there are no BIAB designated tracks to generate which is true since you previously changed the first 8 BIAB designated tracks to regular Tracks.

RealBand does not have that 255 bar limitation other than it will only generate the 8 tracks designated to BIAB. "I opened a .XML file, not a BiaB file." is why I think you did not generate any tracks. You need to select a BIAB Style or BIAB tracks to generate.

As a test, I generated 16 bars of BIAB tracks to a chord progression and loaded _STEPUP.STY. I changed these 16 bars of BIAB generated style to Regular Tracks.

I reset the 8 tracks to BIAB Tracks.

Then I set my song start to end markers 1 - 276 which set my song stop limit at end of bar 276 - according to the from -through selection that is 276.4.119. I added a chord about every 16 bars and regenerated and RealBand rendered the full 276 bars of the track of the BIAB tracks and did nothing to the 5 tracks I'd converted to Regular Tracks. All tracks used were all RealTracks.

I removed the RealTracks and Style and loaded an All Midi Style - 60spop16.sty and repeated the test and it also generated tracks beyond the 255 limit.

In this simple test,RealBand did generate tracks beyond the 255 bar limitation.

Hope this helps you out.

BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.