This is true, @bru! Not a bad point to mention. I noticed the same running quick LFOs into the inputs. In some ways, this produces a nice mistake, too, however - unpredictable results are great. Sort of like a slow response sample and hold, where the peak or fall of a waveform would glitch from the backed up framerate. Not ideal but if you’re recording at the time a pretty fun way to catch an unplanned accident. It’s not entirely a CV you can plan at high framerates, though, you’re correct.
I’m not sure what the allure of FM modulation would be, really, at least for a reverb? A really great use of CV for something on a reverb is to use a slow waveform for the time and tail of a reverb itself. Or wobble the pitch slowly. I’d imagine you can pair that with its audio going into a VCA for the FM modulation component. You can feed the reverb output into an oscillator mixed with a second modulation source too for similar results.
If FM speed is a goal, a really cool thing to do with the FX-1 chip would be to send FM modulation into a oscillator and then use a gate divider to divide that to around 1/16th modulation into the reverb, so it’ll trail in sync with the modulated signal but you’d still get space and delay audible in the reverb.
