That's a very thorough assessment.  I don't have the Mobius or the ModFactor, as I use alternatives.  But both companies are on my radar for modulation and time-based effects.  As you've pointed out, Strymon and Eventide each have their own quirks and advantages.

There seems to be a call for that (as well as user-defined patterns for the PF Harpeggiator).  Each time this comes up, I wonder how it could be implemented.  The encoder/multi-function footswitch combinations are about tapped out (no pun intended).  It's debatable how user-friendly that kind of implementation could end up.

A rewrite of FactorLib is a possibility.  A small popup utility to graphically enter a user sequence for each device in the Stompbox line.  Pitch / groove / effects in the Harpeggiator (PF), tremolo / "slicing" in the MF, etc.  Pie-in-the-sky here, but I'd personally love to have control over those "glide" steps in the Harpeggiator.

I suppose it'd be possible to read an incoming MIDI file (with or without an editor involved).  MIDI Note Numbers being read as relative pitches, or notes and rests in a 16-step grid determining a tremolo pattern (or groove pattern).  These are all stereo devices, so it may be best to have at least two user-defined patterns available.

That said, there are ways to control the PitchFactor externally, and add user-defined pitch and amplitude patterns right now.  Aux switches snapping between sync rates, looping sequences of CC values, MIDI pedalboard switch sequencing, an upstream autopan switching between inputs, etc.  A lot of that involves hardware that you don't usually find in a standard rig, but it can be done.