Thanks for the suggestion. I'm not familiar with Stacks, but notice that there have been a few comments on the forum suggesting that, in the absence of sidecars or other more stable storage of iso data, the use of Stacks can be unreliable.
I'd be happier if possible with a simpler way of sifting the tracks, but my skills with using expressions are limited to the more straightfoward usage.
There are ways to workaround, but NOT to only show Multi if Multi exists (no if, then)
I made some custom fields that show "high res", "cd rip", "remaster", "multichannel", etc, then just made some views to sort it nicely. It works well, although I'll technically always see all of the album versions they are quite easy to sort through (or make a view that shows multichannel only, etc). These custom fields auto tag based on a smart list, so I don't have to do too much to fill them
I played with stacks some, you can successfully make the album you want (multi) to always show on top, but I have yet to become a fan of stacks in a visual way so for now im not using them much