I have seen & flown a Nexstar with a flat (no dihedral) wing & a .61 towing it around -- awesome machine. The wing mod was fairly fiddly & the firewall had to be squared & re-inforced, plus it needed relocating stuff to keep the the CG correct, but it flies beautifully. If you are a competent builder, & a decent pilot, I would say go for it. --- Hell, go for it anyway & put it away 'till you can handle it -- it will keep you entertained for a long time.