i re inforced the fuselage the F-3 on all my 4 stars.

add tri to the fuse/ bottom tail wing

i also add a dowl to the front on the vertical stab.
drill a hole in the reaest former. this way the vertical stab
gets lock in. drill dowls into the fuselage and vertical stab post
to lock it there also. i do add tri on top of the tail wing and
vertical stab, but is only to blend in the deck's line.

i also use a different tail wheel set up . it's just so all the
force won't be on the rudder.

i re inforce the land gear mount area.
using nylon bolt helps, but i get tried of them breaking.
metal screws won't break but the landing gear mount area
gets rip. i don't skip on epoxy there.

i also use the gear from my .60 on my .40 4-star.
it's to give the prop more clearence. the gear supplied
bends after a while.

i usually clip the main wing total 3", take out the dihedral.
leave out the washout and extend the rudder.
the plane rolls will , unlimited rolls... if i pratice.
little or no input of elevator when inverted.
unlimted outside loops with a .46 size engine
the plane still retains decent stall or low landing speed.