I've made some more test with my Moog MP-201. Kept the setting for maximum speed midi transfer and got the following:
From worst to best:
ULTRATAP (all the presets): This is really bad, even with minimal midi traffic it jump from 1 to 100%. The H9 take appear to take several 100ms to update anything.
Any preset with more than 1 parameters linked to EXP: Almost unusable unless you slooowly move the midi pedal. The more presets linked the worst it is.
Any presets with one parameter linked to EXP: Works good generally, but will not always track rapid changes smoothly. YMMV.
MODFACTOR with SHAPE set to EXP PDL (ex: phaser wah) or PITCHFACTOR -> PITCHFLEX : In both case this is without any parameters manually assigned to EXP. This is working EXCELLENT for me, even with fast pedal motion.
The last results (pitchfactor/modfactor) tells me than Eventide did in fact quite a good job tracking midi input when it is done without having to manually assign a parameter via the conventional mapping procedure.
Modfactor is doing this via the "SHAPE" pot, while the Pitchflex algo is doing it "internally". In both cases the tracking appear to be excellent and certainly better than what could be achieved via manual assigment of a parameters to exp pedal.
While I'm wondering about how important it is to be able to have tons of parameters to follow the quick changes of a midi pedal, I should say that the most important one (ex wah, pitchflex) appear to be already excellent at following midi.
I still believe that being able to quickly control say 4 parameters with a midi pedal would be a "nice to have", and also that based on the performance of pitchflex or the direct assignment of the SHAPE parameter to EXP PDL (modfactor) there's some room for improvement that could be made especially when there's only one parameters assigned to exp.
I would in fact like to have a comparable "performance" from a single parameters assigment, to the pitchflex or shape -> esx pdl.
I hope that knowing those limitation will help others to tweak their presets in a better way, allowing them to use a mid exp pedal in a satisfactory way, and hopefully Eventide will have a look at this eventually.