Using "underline" on text including "subscript" parts makes the underline to break (being on a different level and of different width) in the subscripted parts. This makes it look untidy and unprofessional. Underline should be contiguous for all font effects, being contiguous.
Created attachment 158538 [details] A screenshot of the problem
Ok, but kind of seems a dupe of bug 68573? @Mike?
(In reply to V Stuart Foote from comment #2) Most possibly yes; yet I'd prefer to keep it separate because of comments from Khaled, which imply that it might be difficult to fix that for different fonts having different metrics - while in this case, the partial fix could be simpler (just a guess).