Unlimited: 1. limitless or without bounds; unrestricted
Given the set definition of 88 keys on a piano, and the amount of layering specified for the sound engine, 320 oscillators yields unrestricted polyphony.
Definition of unlimited
1: lacking any controls : UNRESTRICTED, "unlimited access"
2: BOUNDLESS, INFINITE "unlimited possibilities"
3: not bounded by exceptions :UNDEFINED "the unlimited and unconditional surrender of the enemy— Sir Winston Churchill"
The word has more than one use as you can see by the several definitions. The one I quoted is sufficient to support Dexibell’s use of the word. If you or anyone else doesn’t like it, too bad. Deal with it. It has unrestricted polyphony.