Houserule/Extrapolation.
The margin-scrawl on p 283 talks about paying for temporary powers, and mentions using tags instead of fate points. The (really old) beta discussions I've read indicated that the developers intended tags to be usable like fate points, IIRC.
So, not clearly Rules As Written, but arguably Rules As Intended.
I'd allow it, even without the sidebar; as long as the aspect with the tag made sense of course.