My apologies, been drinking the Elektron koolaid for too long.
Set a per-step value for a parameter, in this case a MIDI CC, in a sequence. Elektron gear also lets you “slide” parameter values from one value to another across many steps.
I do have Modstep, unfortunately it’s rather buggy and as an AUv3 host would want to be the center of the setup whereas I would like to maintain AUM as the core.