Glyphs too large for the em square.

[Earnestly]

The glyphs are larger than the em square meaning I would have to manipulate the Win Ascent and Win Descent values to make it fit without overlapping rows of text.

To demonstrate consider the following comparison with Inconsolatazi4 (right). Both depict the capital letter 'S' but the difference in height is clear.

Whether this is actually an issue is still to be researched but many fonts do seem to leave gaps above them but not usually the case for real metal casts (pictured upside down).