Why not leave the $250 in the Serve account for a while instead of immediate withdrawal? Is that penny or two of interest you're forgoing of some worry?
Not saying it won't prevent your account from getting shut down anyway, however, perhaps leaving the funds for a month or three might at least give the illusion you're not completely abusing the program if someone is doing a manual audit.
At the end of the day though, it doesn't really matter, it's only $250 CC spending a month. A more drastic loss would be AP.