Looks to me that Inox are
distributors rather than
manufacturers:
Our A2/A4 fasteners are mostly of European origin
Products machined from T316/303/431 alloys are made by local machinists
Bolts come in, you order them, bolts go out. It's obvious from his recommendation for copper anti-seize that his understanding of galvanic corrosion and the galvanic table is limited, at best.
Talk to any mechanical engineer about using copper, stainless and aluminum together and you'll get an earful. They just don't mix. It's why you shouldn't use copper and aluminum wiring in your house, for instance; in fact, there are special connectors that are required if you must do so for some reason.
Again, if Copper was meant to be a ubiquitous cure-all, manufacturers wouldn't have bothered formulating other types, especially those aimed specifically at Al/SS interactions. Frankly, I'd rather listen to the anti-seize manufacturers in regards to what to use; it's
their business, after all!
I'm not sure why it's so tough to consider anything but copper... it's just as easy to get the right stuff and not take chances!
But, it's your bike - do whatever you want to it.