I hope that you don't mind me 'piling on' here, styrioci.  (It sounds as if you've resolved your request for the moment.)  But your quote below sounds a lot like a feature that would be a good fit for the PitchFactor, too.

In the H901/H949 algorithm, the REPEAT function under Play mode seems to play back a fixed buffer of about 200 ms.  Now, if that buffer could be made continuously variable … it'd have to be a gesture such as press & hold REPEAT — turn the encoder to change the buffer from 10-200 ms. (or whatever) – release the REPEAT footswitch.

I wouldn't think that there'd be more than 200 ms. available.  But if it was dialed down to tens of milliseconds or so … infinite sustain of three frozen intervals .  One small change adds a Freeze-Hog pedal on steroids to the feature set.  I don't know about the DSP challenges, or how the code is written.  Sounds relatively painless on paper, though (doesn't it, Russ?).