[itsme]

Sorry if I was unclear.

- using the same font that I would use for a {comment}
That's how Sciurius renders chords in comments in the reference implementation - so this is the most compatible way. That's what I'm usually asking for. 
In case of chords in comments I would prefer to keep it as you currently do it in {comment sections: render chords like in chords & lyrics sections. I also posted in https://groups.io/g/ChordPro/topic/111384559 that this would be my preferred style.

- should I use the grid text size setting for the comments
Definitely yes. The font size of comments within grids should be the same as the chords.

Here's how I personally would prefer it to look, transposed from A to G, source attached
   

But I'm still discussing the topic with Sciurius in the post mentioned above