I'm also interested in this. I know there's an article on Sustainable Village (the US distro for blumats) about using it successfully with a fairly large rockwool grow successfully.
Never used rockwool or bluemats, but I would imagine it would depend on how well the rockwool can wick the moisture out of the bluemats or how saturated the rockwool would stay
Found it: https://new.sustainablevillage.com/blumats-in-grodan-or-rockwool
I don’t think it would be an issue. My understanding is that they work in basically every medium except stuff like clay pellets, where it’s impossible to form a good contact with the blumat carrot