I've never had a problem with mine on the brake rollers only issues when they try get it off they normally go pale and ask me to move it about afterwards.

I had one mot test done where they had an above ground 4poster it was wet out and the tester didnt want me to put it on even tho I offered - it spun up an was sideways in the ramp he asked me to move it afterwards and I told him no cos he parked it.