I timed the render in the Plugin compared to exporting the same separate tracks for the above-mentioned test song in BiaB and the results are similar.
Back to fixing the OP issues.
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=585534#Post585534


Studio One (latest version), Win 11 23H2 , i9 -10940X 3.3 GHz, 32GB Mem, a 4K 40" monitor, PreSonus Studio Live III Console as interface/controller. secondarily test on Reaper, Cakewalk, and S1 on Surface Pro 3 Win 10 (latest versions).