Not really sure why i had the issues i had, but they've been resolved, I think. Giving an update to give this thread to give it closure, so-to-speak.
Only thing i suspect is, i still had somewhat high ethanol content in my tank somehow. Filling half my tank with 91 seemed to resolve the issue. I had about ~20% of ethanol according to my flex fuel sensor and this was after i filled the tank with 91, so im assuming that there was more ethanol in the tank. The fuel trims even improved, from 20% to under 10%.
JDL kit is installed and everything is finally running as it should.