I think that error pops up if you also have brsar open with another file at the same time, like if you open it with BrawlBox after opening Super Sawndz or something.
As for Metroidy thing. I say Samus Returns, for the explicit reason that nothing's been done with it yet. There are quite a few things from the other two already, so why not let something newer happen, haha.
I just asked for linkle's model, just waiting on a response. I was surprised, a friend just showed them out of the blue in the discord server that I'm in. So i asked for them so that i could import lagless versions of Zelda, Sheik, Ganon, and Link(Update).