(2)450 DP's vs (2)750 DP's

I’m really liking the increase the mains thought. What size TSR are you thinking? .065 ish? Also, by reducing the TSR won’t that cause an even leaner issue? Or will the increase in the mains increase the need for smaller TSR’s? Just trying to follow the thought process here.
Might try both changes but one at a time. I would do mains first.