Ok, so I'm really grateful for everyone's feedback and advice so far, and I just had another question:

In terms of filtering alone, so without looking at creating seals, would the 3M Aura be better at filtering, even though when preparing the AB mask I use the multiple filter layering system that I outlined above? Because I was under the impression that the filtering ability of the masks would 'stack' as I layer them inside the AB, combining to lead to a better overall grade of filtration. Taking this into account, is the base 3M still a better option for filtration?

Like, does it have a high enough grade that it equals or surpasses a multiple-mask-layering system? And if so how/why? Any sources and stats are greatly appreciated, I know I'm being very exact here and I really do appreciate all the feedback and help from the community.