E-Flite Carbon Z Cub

[Whizzer]

Crashed my E-Flite Carbon Z Cub and severely damaged the wings to the point of replacement rather than repair due to pilot error. Not once but twice!! My question is, if new wings were bought and I did not use the vortex generators, how it might affect the performance of the plane if the slots where the vortex generators normally go were filled in with a light foam type material typical for repair of EPO airplanes.
Any thoughts?
Or, an acquaintance has a Z Cub also but his fuselage is damaged beyond repair (split, broken in three serrate pieces and he is making noises about getting out of r.c. flying. He has a set of wings that look like he tried to chop the wing tips. Says he had his plane stored close to the ceiling and when taking it down, stuck it into a high speed ceiling fan. I was wondering if I were to get the remnants of his derelict Carbon Z for parts and cut the wings about three inches shorter than the normal length, rounded and shaped them, how that might affect the performance.

[Alpha]

Whizzer Two times is tough, I've been there!

I would not recommend filing in that gap.

Shortening the wingspan will increase its roll rate and speed while reducing its stability. Rounding the wingtips may introduce other behavior, especially if the two wingtips aren't shaped identically.

If you really want to do something like that, I would recommend at least doing so in gradual steps. First, clip the wings in a straight line parallel to the fuse, in a small increment, like an inch. Test fly it. Clip again, if desired, test fly it again. Repeat until satisfied, then turn your attending to rinsing the wings. Consider making a jig that can be reversed to plot the opposite wingtip. It doesn't need to be perfect for foam at this size, but the closer the better.

At the very least of it were me I would lay both wings together, underside wings touching, then carve the curve through both wings at the same time. Keeping them sandwiched together, you can then reprofile the upper sides so that they're close in shape when viewed from the leading edge and the trailing edge.

[Whizzer]

Appreciate the feedback. As a bit of novice myself and not used to aero, lift, etc., nuances, appreciate any information that will help me make a sensible decision.
Whizzer