I love the idea of custom effects. I have used Max for Live in Ableton 11 Suite and I currently keep an Empress Zoia on my pedalboard next to my QC.
A Max collaboration is a really tough sell at this point while a desktop editor for QC does not yet exist (NDSP have confirmed that it’s being worked on, don’t @ me about it folks). Maybe in the future that could work out.
In the meantime, here is a request for LFO / gate / envelope controls to make QC parameters more customizable: