I did both the shower and Kyle's prep at the same time once and I didn't notice any extra swelling of my face or undue inflammation. Neither did I notice any significant beard softening. There may have been a little extra softening but not enough for me to warrant the extra effort.
I would reserve Kyle's prep for the purpose for which it is intended. Pre-shower or without a shower. If you like to shave pre-shower it should work well. I personally like my shave to be the final step in my morning routine so Kyle's prep is not for me.
What did enflame my face and irritate my skin yielding a very poor shave was using very hot water for prep and shaving. I stick to nice warm water post shower and everything is good.
TOFLAC-U, AOM, LEMS/ Stay back! I have a Merkur, and I know how to use it!