I current have set the current line number face to be bold:
`(line-number-current-line ((,class (:foreground "#4F4F4F" :background "#00CC00" :bold t))))
When I move the cursor between lines, there is a very unpleasant movement of all the text, as the line with the bold text takes up a little more height, so that line gets taller, and then contracts when the cursor moves past it.
This is just a single example of where this issue is popping up. Another example is if any highlighting makes the word bold (e.g. matching parenthesis).
If I change the line spacing, there is just extra space between the lines, and bold text still expands even though there is adequate space.