The clipping is very evident when it happens, it's not something you'd miss. I know pretty exactly where it happens on both my Clear and Utopia from specifically going checking for it, and I know that level is
well above the level I listen at, even with heavy sub-bass tracks and even with full Harman sub-bass EQ.
It's certainly the sort of thing that if you do hear it, I'd turn down the volume immediately. But it's not the sort of thing that could be subtly happening in the background doing damage that you don't notice, it's
very obvious.
As to whether it is a direct cause of the driver failures, I don't know. But driver failures do not seem uncommon, and it's not just the Drop collabs, they seem common on the Utopia as well. I got my Utopia second hand, but in basically brand new condition- it was a replacement for one that suffered driver failure. I got my Clear second hand as well, and it was the same, it was also a replacement after driver failure.
The older model headphones seem worse for this, this is what Focal said about it regarding the Utopia, they admitted they had a specific issue but claim to have fixed it. I think it's least apparent in the newer models, I think they changed something with the voice coil in the Clear which reduced it and my subjective impression from reports, the Clear MG seems to be even less reports of it again.
https://www.head-fi.org/threads/focal-utopia-general-discussion.811273/page-590#post-14515753
I get the impression the Drop collabs like the Elex were worse again, but this was an issue with the Utopia too.