View one track in piano roll while editing another

I have several software instrument tracks.

Track 1 has my chords.

Track 4 is where I want to place new notes. I want them to be chord-friendly but don't necessarily want to duplicate the chord notes, so I have to be able to see the track 1 notes while I'm working.

I want to view track 1 in the piano roll while using the pencil tool to click notes into track 4 in the same piano roll without having any effect on the notes in track 1. That is, I want to be able to make my decisions on which notes to add to track 4 based on the contents of track 1, using track 1 as a visual guide only. Is there a way to accomplish this without actually copying the notes from track 1 into track 4 and then getting rid of them when I'm done?

Does the answer change if the track 1 region runs from the start of measure 1 to the start of measure 3, then loops, while track 4 starts in measure 9?

Logic 10.6.1.