Quite a laborious experiment.
-) it is always fine to have a working formula at hand from which to deviate for specific experiments.
-) for those of us who undergo difficulties in obtaining industry C-41 chemistries, a formula for a homemade developer could be a solution
-) some may consider doing so just for cost-effectiveness
But keep in mind that Flexicolor sets the standard to which other companies have to design their films as long they want them to be processed with good results in chemistries who follow this standard.
Thus films are optimized for a given process.
(In theory there might be a C-41 film being processed in a custom made developer bearing even better result than Flexicolor.)
You however designed a developer for a given film.
It could be that with another film your results would not be that much in line with Flexicolor.
Thus any comparative tests should be done with several types of C-41 films being processed.
(I do this remark as you did not state how you ran your tests. Perhaps you already did so.)
Seemingly this is a one-shot process at the moment.
Are you thinking of doing several runs (time compensated or replenished) in future?
How do you do the `dry pre-warm´? Just by letting the drum with film rotate for a while in the warming bath? Or do you use temperated air?