Enlarging the ailerons on the tips could promote flutter since they are strip ailerons. The Sig Kavalier has that problem at high speeds. Also, the tips is where you will be vulnerable to either tip stall problems, or vortices for sure. The best bet is to narrow them at the tips and widen them towards the wing roots. The flutter possibility is remote, but vortices interferring with aileron control isn't.

There was a website with mods to the 4*60 but I think it is down now. This is where the guy shows how to carve a nose cone block. He turned his canopy around and angled it to make is smaller, if you can visualize that. It did look good. The site was www.renderwurx.com/rc/sig4star.