Unfortunately, your suggestion non only didn't work with pools and datasets but my .DS_Store files are not created anywhere any more now...
It gave me the occasion to dig a little more the Internet about that issue, just to find that it happens to other people, presumably not using ZFS, and from Yosemite to Mojave.
So I think we can consider it a bug in MacOS, as some other people say, not related to ZFS.
EDIT: while I was writing this post, it started to work again on my HFS volumes! Looking at the Console, it's full of quicklookd and QuickLookSatellite errors... Well, we can at least say that this MacOS thing is not reliable at all.