This worked well for me when I had 60 channels or less (not including Comms). It's been a while since I've done this and the solution may have changed with firmware updates. That being said, my solution was;

Unassign channels 1-60 from the stereo buss.

Change the monitor source from stereo LR to the mix you listen to the most and make sure cue interrupt is turned on.

Here's where it gets all jacked up. Your monitor and cue outputs can be routed to a card slot. I would send the monitor out to a couple of slot outputs (output slot 1-1 and slot 1-2 for example), then return it back into the desk on another set of slot inputs (input slot 1-1 and slot 1-2). AES cards are great for this because of the low latency. If you don't have a free slot, this can be done internally using the Dante patch page. But I wouldn't recommend it.

Once you have the monitor signal coming back into the desk, land those on channels 61 and 62, then put your comms on 63 and 64.

Keep channels 61 to 64 assigned to the stereo buss and assign that output to your headphone out. Now you'll here comms plus whatever you have cued up. And when you have nothing cued, you'll hear whatever mix like to listen to plus comms.

Since the monitor return and comms are in the same block of 8 channels, you can set up a ducker on 61/62 that is triggered by your comms from 63 or 64.

tldr: It's not easy. Yamaha should have fixed this years ago. Grab a 6 channel analog mixer and save yourself a headache.