After reading the README, these were the things I found missing that I'd like

* Detect system fonts
* Set size of font
* Highlight whitespace at end of line
* Colour background of specific column ranges

I don't know if these features exist somewhere that I didn't find, or if they are better off
being implemented in my customisations?

Yep those are all missing features right now.

Getting system fonts is on the todo list, and I've just added run time font size changing to the list.

I'll think about the other two for a little while. I think they will fit into my longer term plan so I want to wait until I start seeing how that shakes out to know for sure.