Becareful,

Fair enough reasoning although not fool proof but you do acknowledge that.

I wonder how the timing of the flucs on Betfair compares to the "real thing" on course. Would an on course spotter have time to relay the firmers to someone off course linked to Betfair and back them before they firm and then layoff. Takes the risk out of your actions becareful.

If the flucs are almost simultaneous then it clearly wouldn't work.