Uhhh good question, alot of this I learned thru my many years keeping aquariums along with growing.
I have found there are a lot of really good solid info, on BB cultures on Koi forums.
Many of these people, have koi’s for a 100K in their ponds.
The enzymes and BB cultures they use, do the same as the stuff you buy in the grow shop.
Different price, and much bigger buckets/jugs.
So I would try and find a serious koi forum, the are likely to have a section about filters. There you should be able to find loads of info on BB cultures and enzymes, that break down waste nutes and organic matter.
I think molasses is pretty much molasses, I have not researched it. But my educated guess is, the mycelium won’t care what bottle it comes from. It’s a waste product from the sugar industy, but it rich in different minerals. So it also contains, a few things the plant can eat, but not sure it’s acceable to the plant untill it’s been broken down.
Here im a bit lost on where to go read up on mycology, and how the mycelium and root network symbiosis work.
It’s a long time ago I studied this, and not in English, but there are a bunch of different things playing in.
Both enzymes and mycelium will eat molasses, I used the cheap animal food one made from sugar beets. No idea if canesugar molasses is better/worse or the same.
Hope this helps a little, guiding you on the right path