My Razzle was balanced about 14mm further back from the recommended extreme aft position. This plane would waterfall like no other as well as did climbing flat spins.
It never did do good knife edge. Terrible roll coupling.
Got the cg back by mounting a 5 cell 1200mah battery in the fuse behind the wing saddle, 4/40 pushrods & hardware on the tail, coreless/bb servos & a stronger tail wheel assembly.

Lost it on a failed rx. Reminded me of the old free flight days. Sure miss that plane.

Ken