Integrated Fin Can for supersonic flights on 38mm minimum-diameter rockets

I have flown this several times to Mach 1.9 (according to RockSim) since the fins are perfectly aligned every time. All you have to do is print it (10% fill, normal speed print, with rafts) and epoxy the fin can a quarter-inch or so above the bottom (so you can use a ring of duct tape for motor retention) of a 18" (or longer) strong 38mm motor/body tube (it is perfectly sized for Blue Tube) and tape a golf ball to the top (range balls are free nose cone + weight, which you will need). If you h