Thanks for your continued work and improvement on this, Dismounted. I did all the edits/updates you've shared here, and it now appears to be working for me everywhere (in both the default vB skin as well as my custom skin.) As the original requester, I certainly appreciate this enhancement!
There's one last location to "Mark All Forums Read" though that could use the confirmation pop-up, though. New in vBulletin 3.6.x is the ability to double-click the icon to the right of a Forum name... that marks that particular forum as "read."
See here:
https://vborg.vbsupport.ru/attachmen...2&d=1145289561
I'd like to get a confirmation pop-up there too, to keep things consistent.