Generally the "lucko fabric permissions API" supports vanilla op levels, without the need for LuckPerms, FYI. Depending on how carpet implement's it's command dispatcher (I haven't looked) it's generally a trivial addition.
Perhaps I can consider a PR.

The Permissions settings are pretty much coded based on Methods under the Carpet Settings, so changing to something like that is possible, but it would also break existing carpet config files if say, someone were to implement a setting of "ops" for the permissions. So, the permissions check functions need to basically be re-written, along with the config methods to make this work; and then come up with a "standard" method for the Luck Permissions nodes that all downstream dependent carpet mods will need to implement...
So it's not quite that trivial on second thought.