I understand where you're going - and it's valid. There are cases where you run out of rope within 8 PARTs and would want to be able to have more.

For the TX-816 E-Piano, however, since the TX-816 is a 6-operator device, you could refactor the Algorithms such that you can combine some of the operators from one TX-816 module to use an 8-operator alg instead of 6-operator alg. It would take some time to refactor - but you may be able to recover a PART doing so. I say "may" because the devil is in the details. I don't have the programming sheets for the TX-816 E-Piano to review.