Upon further thought, I prefer a radio-button to select before OR after stripping ENUM lookups (make it default to before). Doing it BOTH places opens the door for an unintended ENUM match.

This may not be the best example, but...

You want to use a prefix of 01 to specify a particular provider. The number to be called is 1 (222) 333-4444. The unconditional ENUM lookup before checking dial plans is 0112223334444, which looks like an international number format and might find an ENUM match that's NOT the U.S. number

A radio-button lets you make sure the intended number is looked up in ENUM.