I don’t think you can go wrong by using the H910 / H949 algorithm as a starting point.  Very versatile:  TYPE will take you through a short history of pitch shifting models.  Parallel 5ths, 7ths, 2nds, above & below Pitch(es) at 1.000.  The readout is in decimal ratios, but easily figured out by ear.

Start with Chromatic Pitch Control.  But don’t ignore Smooth control, for ‘almost there’ pitch intervals.  I usually start with a Type model, but always select a Pitch Control parameter before adjusting Pitch A & Pitch B.

Another algo that immediately comes to mind is the Looper, for the earlier Stockhausen / Riley music.  But Hassel continuously moved on up to better & better Eventide units.  So there are a lot other algorithms that could apply here.