I havn't had any issues breaking the extended wheelbase arms, though when i tried to move the pivot balls to th 10mm setting the arm cracked at the thread.yeah it might be worth giving those a try as mine break at the ends and that appears to be what is beefed up on the summit's axles.
Toys:
Slash with VXL
E-revo with MMM/Teckno Nue 1515/1yf running 4s and 5s