They are a PITA!!
Seriously, the gear leg length needed for e-power planes would be very long; so to reduce gear flexing you would have to use at least 3/16" wire which gets heavy, plus the servo , linkages, etc. Back in the '90s, an Australian pattern flier named Peter Goldsmith (now living in the US) did some wind tunnel testing and discovered that fixed gear (streamlined & with wheel pants) had significantly less aerodynamic drag than retracted retracts. The only way retracts provide an aerodynamic advantage is if there are door covers for the retract wells that are air tight. Fixed gear has much less maintenance, too.