I don't think switching to barnblitz pro will fix the problem.
The issue is the 32 players and the shortened respawn for red.
The only way payload is remotely balanced is to have 20+ second respawn times for red, and even having that, red will still win 70% of the time or more. That's how poorly designed the maps are.
We used to have 20 second respawn times for red at the last and/or second to last cap point and everyone complained about it, so it was dropped to 10.
Maybe having an engineer cap might help (most pubs can't coordinate more than 1 uber) but people generally hate class limits. If it was something high like 8, then maybe it would be tolerated. But then it might not make a difference.