Without delving into the physics or background, do we want to touch the MFRAC limit or keep it stock?

When I kept it stock at 1.05, I'd see my MFRAC PID peg out at 1.05 towards the revlimiter. I raised it to 1.50 and it creeped to 1.48
Do I want to keep it stock at 1.05, reduce it, or increase it?