The DP can tolerate a CG further aft than where you have it right now. I'd say try it about 1/2" behind where it is now and see how it helps. I just noticed you said the plane seems to over rotate a lot - what I like to do for sequence flying is reduce the rudder travel until the overrotation is minimized or stopped altogether. If you need more rudder for Hammerheads or other maneuvers you can flip the switch to high rate, though I've found it not to be necessary for the most part. My DP Extra was in interesting beast - it definitely flew differently than my other Extras. However, once I got it dialed in it flew precision very well. As far as scoring snaps in IMAC, I've seen some "interesting" looking snaps score very well, so I wouldn't be too worried about it. Looking forward to talking with you again at some competitions this year!