I'm probably not the only one here with a piece of Moog gear.
Aqua boy or zero point super deluxe with control voltage would be sweet. Or stage fright phaser. Fuzz pedal that can be manipulated by external waveforms. Mutron, etc
my attempts to voltage control aquaboy were not great. Zero Point should be awesome for this. Search the forum, you can add CV inputs by using LED/LDR combos to create voltage controlled resistance then putting that in parallel with a pot. the pot values have to be within a certain range but this can be a fun mod. I even added a cv input to my 1990s EHX Deluxe memory man this way
Strategy
Also some Lovetone have native CV, really robust i/o options like moog pedals: Ring Stinger (see DIYstompboxes forum project String Ringer) and ? Flanger with No Name (Electricstorm project in this forum and diysb)
strategy
Modulation, it could be worth doing a straight patch in (with a switching jack replacing the line from LFO to wherever the LFO goes, taking the plug out restores the pedal to stock LFO). If I'm seeing the ZPSDX schematic right, if you apply a constant voltage or offset through the modulation in, you can change the delay time as well (no idea how much, can't be bothered mucking about with my zpsdx atm.)
The Stage Fright has the two CV pads, normally you link them, but you could put a switching jack in instead.
Just woke up from a nana nap, probably not too coherent.
I did try patching the Ring Stinger's VCO into my Eurorack synth (using some 1/4" to 3.5mm converter plugs), worked very well.