Adaptive track outputs in track mixer cannot be muted unless A16 is also muted

Bug, previously reported, still extant in Adaptive audio track workflows - it's not possible to mute individual outputs in the track mixer routing for an adaptive timeline track unless A16 is included in the mutes.

The project at the link below is a simplified timeline to show the bug.

 In this timeline track A4 should have A1&A2 outputs muted, but all tracks pass if A16 output is unmuted. 

https://drive.google.com/file/d/11k5m1Xf8jLEjxuBgh7w5f0SlsfRwQ5Ce/view?usp=sharing - collected project example.

I realise this is pretty niche use of adaptive tracks, or others would have noticed. We currently do this work in Avid but every couple of years see how it would be possible in Premiere.
This is in v23.4 beta on MacOs 11.6.8