Tap away.
Charlie Vernon taps his foot pretty much all the time while he's practicing, and anything (attack, slur, whatever) that doesn't happen at EXACTLY the time he intends is something to go back and do again.
Timing is SO important, whether or not you've accepted a diagnosis. In my lessons with Ray Premru in college, I often had problems starting a quiet middle D, and since he often had me working on the Prelude of the 2nd Bach Cello Suite it came up often! Ray never gave a name to the problem, he just showed me - over and over again, with infinite patience - how to start a note with a simple breath and a simple puff, timed beautifully and naturally.
I think that over time you can reduce the foot tap to a motion of a big toe, that won't be noticeable to other players or an audition committee, but the tap is a useful tool - IMO, there's no reason not to do it.