Sumu Preset Sound Design in Sumu b14 Early Access by Madrona Labs 

Thanks, it's definitely an interesting sound design tool, it's really fun to explore. I did another video where I was making drum sounds, so it's not only for experimental sounds (but wouldn't generally be my first choice for more intentional sounds). You can try the demo to check how it performs on your system. This is still a very early version and Randy said he has more work to do on optimisation. I managed around 16 instances with around 50% CPU on the meter in Bitwig in my percussion video with 1 or 2 voices for most of the presets. Win 11 with 13th gen i7. Keep in mind that each voice has 64 partials and each partial has a 2nd oscillator for the Fm and noise, and there's effectively 64 envelopes etc, one per partial - so by design it's going to be a lot more taxing than a regular subtractive synth.