I would love a more usable synth algorithm. Something with features like the EHX Microsyth and/or HOG and polyphonic, e.g., more control over ADSR, distortion, and clean mix. It just seems somehow complicated and limited right now, which is probably why there are only 5 fun but pretty much unusable patches.
Octaver that has more octaves and more control over them, e.g., -2, -1, +1. Also, digital and analog modeling octaves options.
Reverse envelope filter in the q-wah algorithm with mix control and compressor combined. The new Sculpt algorithm at least has an envelope filter with compressor, but not with reverse envelope. It would also be nice to have more control over the ADSR in q-wah.
I would also like the ability to start any algorithm from scratch instead of modifying existing patches.
Polyphonic tuner algorithm.