Firstly I would like to point out that if you remove your topic, I cannot read your reply and see what your problem was after all. Other people that might have a similar problem in future cannot either.
I can add warnings for ascent/descent/linegap not adding up to emSize and duplicate characters - the deal is that specification doesn’t explicitly define how the font should be rendered, and thus implementations can vary by a lot. Most of the existing information in field tooltips comes not from expert typographic knowledge, but from people having informed me that doing something causes specific software to not render the font correctly.