I am showing line numbers with a font size of 50. I have changed the minimum line height to 50 so that all the line numbers show up in the line margin. The text for each line is vertically aligned at the top.
No problem, I looked at them. In v4.0 text in the text area is rendered using a baseline so that multiple fonts can be used. So it ends up being more like your bottom-align picture. Although the line number margin text is still centered in the display line. Is that sufficient?