Hey, for the past couple of weeks, I've used Porkynator's variation on ZZ-d quite a bit. I did a 15.90 avg5.
But I've noticed a few things:
-I get my fastest times when I build the left block first. This has more to do with the recognition than the regrip, though. With enough practice, someone should be able to be "side-neutral."
-You can recognize the relative corner permutation by applying your "understanding" of the corner cycles from standard COLL algorithms. By looking at groups of corners on the top layer that resemble COLL cases, you can identify the corner permutation with ease.
-Although it's obvious experienced solvers, L' U R U' L "swaps" the UBR and URF corners while L' U R2 U' L "swaps" the DFR and DRB corners. You use these 2 algorithms to solve or diagonally solve the corner permutation. This is the way I think during the cp phase.
-It does not seem that difficult to recognize the cp as long as any 2 corners are correctly permuted with respect to one another and placed at UL or at DR. For example, with UBR and UFR at the bottom right of the cube, it is easy to see what must happen to the other corners to solve or to diagonally solve the corners.
-Another thing that I noticed was that if you solve the DR corners and isolate the left block pieces first (as in ZZ-rainbow), then you can manipulate the way you solve the left block such that the cp will be solved afterwards. In other words, during the last slot of the left block, you can identify how the U layer corners must cycle in order to solve the U layer corners with respect to the D layer corners you already placed. There would be more cases than zz-porky, but it is not impossible.
-You also get fast times when you remember the 2GLL algorithm!
Please try ZZ-d (Porkynator's variation), and explain how you think it could be improved. I think it has a lot of potential!