From my experience and observations toe out on RC planes is better than toe in. Reason is toe in on a poor landing will promote the plane to trip over its wheel and help it to begin a cart wheel. With toe out if you place one wheel on the ground while in a yaw the wheel is pointing outward when it touches down. As another member mentioned it can cause the other gear to slap down but the toe out geometry will not induce a cartwheel or wing tip scrape as easily.
Anyway Ive been doing this for years, suggested to everyone in the club that has issues like this, and I have great landings. The planes track down the runway at full speed just fine as well.
I dont suggest this for tricycle gear only for conventional planes and especially for planes like Spitfires, Bf 109, AT-6 and any narrow track warbirds. I do this for all of them regardless though.

Also make sure your axle is in front of your wing leading edge or as far forward as your model will allow. This coupled with toe out really inproves ground handling and prevents nose overs.