I think you're misunderstanding his question slightly. Based on what I know - your forms are decided when you select your focus. This also includes some checks to make certain you don't end up repeating a form in the case of double focus, and I believe at some later point, checks to ensure you don't end up with absurdly repetitive forms like tortoise/armadillo.

Given that, you're answering whether "Are these non-repetitive forms still off-limits when I roll". Which means now you could roll your tortoise/diamondback and end up with tortoise/armadillo.

My understanding of the question is "I had tortoise/diamondback, rolled it and got mongoose. Can I now pick a minor focus and vet diamondback again." Unless specific code exists to track your old form and prevent it, yes, you can, and I would guess its such an unlikely scenario that no-one would have written the code, so I expect it is possible.

(I mean...hero, roll, THEN pick the same minor focus, AND be unlucky enough to double it up? Yeah, just pick your doubled minor before you spin.)

That said, I'm also the guy who played util/util and got spider, baboon, howler monkey, and orangutan. Yeah, I lasted two weeks before I couldn't handle it any more.