I feel like there is room for more of a semi-modular delay module; Or, I am thinking of a delay with send/returns. What about a mod matrix or patch breakout.
I feel like there are several stages that could be controlled. For instance, this envelope is neat because the modulation stages in the ADSR are broken out.
So, you could have a send/return effect at a certain spot in the routing of a delay module that could be set off at a certain stage of this ADSR.
Again, it would be nice to be able to insert the fold stage for adding harmonic somewhere in the middle, rather than before or after the delay.