This is what FCOM 3.05.06 P1 has to say about it (for the A320).
Maximum continuous
It is the maximum thrust certified for continuous use. This rating should be used, at the pilot’s discretion, only when required to ensure safe flight (engine failure).
...so a little vague as usual. Wouldn't use it myself to meet an ATC restriction; I'd have thought winding back the climb speed would have a more significant effect.