At first I had a GMS .47 and it flew fine but I changed it for a ST G61. it had great vertical but was nose heavy so I cut a little compartment at the rear underside of the fuse and mounted the battery there. I still had to add some lead to the tail, she came out to 6 3/4lbs. The wing loading was pretty high so snaps were sooner than normal and landings had to be hot.
My firewall never came out, only the landing gear because of the poor glue joints around the landing gear block. I rebuilt the whole landing gear block and she was good.
I had my balance point at 4 inches so it was Very responsive, it would snap with the low rate setting on the elevator (1/4 inch) if you wanted it to.

Build up speed for takeoffs and let it gently lift, and keep a gradual rate of climb. Don't try and muscle it off the deck or you will quickly notice it drop the right wing.

Your irvine .53 will move it around nice. Hope you enjoy it.