[nickfargo]

I have understood “performant” to suggest a soundness of design that causes something to be “fast”. In the context of algorithms, certainly the distinction is blurred, but in other, higher-level contexts, it can be meaningful.

[qbrass]

The suffix -ant can turn verbs into nouns or adjectives, which means something can be a peformant performant.

I suggest using the -y suffix for the adjective form and -ant for the noun form. Then you can say the performant is performy, or performier than before.