@Azreal
Yes and no. The factory is optional. You do not 'have' to submit anything through the factory. Though, if you are using something against another writer that said writer does not think your character should have access to, they or an RPJ can request that you make a factory submission for said item.
I, personally, would not see anything wrong with "durasteel" crushgaunts. But I do not claim to be an expert on that particular bit of technology.
I do believe, though, that a number of "off-brand" gauntlets have been made that function similarly to Crushgaunts, but without the Beskar.
Typically, they utilize Cortosis or Ionite or some other rare metal.
If you browse the Marketplace, you might be able to find something suitable.
But! From a Factory standpoint. If you submit a suit of armor or any other item that includes canon, beskar crushgaunts, then yes. In that case, you would need to do a suitable development thread.