I've been looking around but I just can't find a reliable source with this info and the wiki says nothing about fort block with follower, just the fortify damage ones do not work.

So, does fortify block work for a follower?

From my understanding, all fortifies work on followers. However I think it's wasted to give them a fortify block when the follower can't really die from enemy attacks. I just always give them something that increases their damage (fortify destruction, one-handed, two-handed, etc) or a fortify that benefits me (restoration, strength).

They are already packmules, so you can have them wear all fortify strength equipment to become even more so as well.

Fortify carry weight doesn't work, I just tested it with lydia. The wiki says fortify damage-skills doesn't work either.