I don't know what you are talking about, yuan-ti mages always supposed to cast stoneskin. If they didn't, then it was a bug in the original. Their script's first action is to cast it (in both games). (View Post)

They get 10 rounds immunity. Vanilla allowed casting only one at a time. We allow more than one, but don't allow repeated damage. (View Post)

Bugfix for this is under testing - it is not too much of a bug, just a small exploit. The item wouldn't be working even if it doesn't show the red highlight. A quick save/reload would fix it. (View Post)

This is a known problem, affects only the display. (View Post)

Well, it should be easy to remove these restrictions in a mod. (View Post)