I have an approach I use for most songs that may be a suggestion to think about.
1. I create markers that make sense in the song. No surprises there.
2. For every song I work on, I reserve the first track to be my visual of the parts. I create a one measure midi block of nothing (no sound) at the start of the song and repeat paste it exactly starting at the start of each measure out for 120 or so measures. So I have 120 or so 1 measure blocks on one track.
3. I use the Clip background color selections to color ranges of blocks differently. If you look at the Inspector pane and click on the tab for Clip you can easily get to the background clip color setting for any range of clips you've selected. This makes it easy to see where the verse and chorus and bridge parts are by having different colors for different sections - displaying across one track at the top of the Track View.
4. For chord changes I do sometimes use the markers to help remember those.
But potentially, you could use the method in 2-3 above to use clip names, Rename clips as needed, to show chords. Just an idea until Sonar is more elegant in this regard.