Just for reference, in case anyone wonders what node you’re talking about in the previous post, it’s this one:
Hmm, very interesting… I was hoping that would ultimately be the solution, as the only possible explanation in my mind would have been some sort of implicit cast or similar things happening behind the scenes. This would also explain why I’m able to retain the behavior separation when editing the Material directly (or so I thought) for multiple meshes and why this doesn’t happen when explicitly creating 1x MID that then gets used by multiple meshes 
. I hope the reasoning of this last statement of mine was sane enough this time (boy, oh boy, I just made a rhyme 
).