I’m not seeing PolyComplex or the like, but I am seeing 3 different Elastique Pro, 3 Elastique Pro Formant, 3 Elastique efficient & 7 different “standard” types available. AFAIK, this is the algorithm used if & when any processing is being carried out in the Pool though (p378 in the Operation Manual “Getting into the Details”) and p322 gives a lot more detail:
Elastique Pro = the best audio quality, without formant preservation
Elastique Pro Formant = as above, but with formant preservation
Elastique Efficient = less CPU, but lower quality than pro modes (LoFi?)
The 3 variations on each of these are as follows…
Time = Timing accuracy favoured over pitch accuracy
Pitch = Pitch accuracy favoured over timing accuracy
Tape = Pitch shift is locked to the time stretch, so stretching the material automatically decreases it’s pitch. Has no effect when used in conjunction with event transpose or the transpose track.
MPEX is not available for Pool functions but is available in arrange window functions (assuming that it is not set to toolbox, right click will bring up a context menu and “Process - Pitch Shift” gives you the MPEX options, but I am not sure where else you will get them.