i agree but timbersled said it's not nessery on the iceage rails i am not sure want to do part of me says cheap insurance like you said but on the other hand those small wheel bearrings going that fast would they not fail fast?
I have a set on ice rails ran them all last year no problems. they are on the end of the rail, so they don,t make contact all the time. but I think they are needed it only takes one time hitting something or alittle track slap and you will stab the track with the 3" pitch.
I always try to error on the safe side, we did extend the tip of the Timbersled rails for Yamaha a bit bringing it closer to the drivers and that should help, but better safe than sorry sometimes