If individual track tempo multipliers is a pipe dream, I’d be happy if there is a setting for a master track length of LCM (least common multiple). That way you avoid the reset to step one and the problems of an infinite master track length. Infinite is not needed without individual tempos. All patterns will loop in a finite amount of steps. The calculation is easy enough, let the RYTM loop naturally.
Edit: calculated the largest loop with 8 tracks with 64 steps available and it was a bit bigger than I thought, a little over 37.4 trillion steps till loop (64x61x59x53x47x43x41x37). So maybe a bit more limited than LCM, but something bigger than 64 and more intelligent than a power of 2.