@eMole: I dont see how hiDPI issues could cause missing buttons, but a screen shot would be useful, so I know what you are talking about.
@rboatright: This commit should fix the issue of small icons in the preferences dialog:
https://github.com/kovidgoyal/calibr...a349e9afc3f05e
You have ay other issues (non-plugin related) I will be happy to look into them.