Friend of mine brought this up, and might be worth considering for a Beta Update at least in terms of clarity of language.
For the Enhance power, the basic power says "spend FP to add Success or Advantage" to the relevant skill check (Athletics for basic power, but the Control Upgrades expand what skills are affected).
Previously, we've been playing this as "can spend multiple FP's to generate additional Success or Advantage." So for instance, if you generated three Force Points, you'd get to add up to three Successes or three Advantage or some mix of the two to your skill check.
However, with the FaD Beta's addendum that says "unless the power or upgrade says otherwise, you can only activate it once ," perhaps Enhance's basic power needs to be reworded to allow for multiple Force Points to be spent on the skill checks?