Yes, for your example you are right. I have never done such type of alignment myself in my code, but indeed there seems to exist people who like that. Indeed for that type of alignment proportional fonts do not work. Really a nice example.
> Indent width can always be freely rendered Yes, with your NimEdit :) For closed source editors that may be possible or not. And for Open Source code, we may have to patch the code for our personal use. For example for GtkSourceView all developers seems to be retired, so there is currently no chance for extensions -- I do not think that my own patched would be accepted. (I recently asked GTK people about indent marks as you have in your NimEdit, or about smart line wrapping. No reaction unfortunately.)