I thought we were discussing ice accumulation on the PCUs, not stab frost. The three cycles of the elevator was for clearing fluid that had got inside the elevator balance cavities, nothing to do with the stab.
As for flap cycling, it appeared on my company's Freezing Conditions before take off checklist a year or so ago. Flap selection is deferred until entering the runway, but I can't remember off hand when the cycle is required, before taxy or immediately before flap selection. I think it's the latter, which would be more prudent.