Shout out to Maverik259, Doberman16, and DuSH for sharing spark resolutions for tuned 50i.
After running with JB4 and Dinan, I switched to BM3 Stage 1. Damn it's amazing. BUT car starting hesitating/shudder during WOT. As I read, the issue only gets worse and it did. Eventually lead to drive train malfunction and the car became a violent, rolling shaker bottle.
Locked the DME and took it to the dealership to have X5M (gapped 0.023in) plugs, new coils, and X5M air filters installed.
Results are that it did the trick! Car runs smooth and pulls amazing. Dyno scheduled for next week before DPs.