Thanks for the reply.
I should have noted that I am using “sync”.
I think I understand the rules, but I’m not ashamed to admit I’m still a bit confused. I’ll struggle through it all until it makes sense. 
My guess is that as this software evolves, and more users are printing with multiple AMS, more features will emerge that help make it clearer what’s what when selecting and assigning filaments across multiple AMS units.
I’ve scoured and can’t seem to find any super clear tutorials or guides on how the Prepare: Filament section works with multiple AMS, and how settings in that section interact with the AMS assignments when it comes time to print…