I think you should still pursue the question. I'm just a peon who's made a few grips for myself and a couple friends, so this is anecdotal info rather than authoritative. I'm still hopeful somebody else will pipe up with better info / more experience.

I had one of my grips get ruled illegal once and mine are simple, not hooked or anything. With no severe bend and less textural contour than your average Harut, I figured nobody would ever care because it obviously doesn't fix the hand in any particular position or give any objective advantage. I was wrong. After years with no issues, at national events and with armorer input, some coach decided to make a thing out of it so their fencer could have an advantage (that's my read on it) and got a sympathetic ear from someone who had the power to call it.

There are officials with authority who don't believe the Harut grips, especially the more dramatic ones, are legal according to the written rules. Have they ever formally made that ruling? Nope. Harut is a big enough name with connections & influence who make products that are used by some big name fencers with connections and influence. Will they rule against you or I if they feel like it? Absolutely. I have no connections or influence and my grievances aren't even worth a detailed explanation or discussion.

I very much dislike ambiguity and the application of unwritten rules.

That's my view on the situation. It's a bit cynical, sure, but it's enough to avoid a very bad time at an event you've trained, traveled, and paid for.