Oh, you mean this one…
I thought you were joking. I didn’t realize you proposed it as a serious argument.
How do you propose this ‘up’ quark in World A and ‘down’ quark in World B came to exist? They just popped into being magically? Yea, sure. This is “physically possible?” Like “possible” as in stretching the idea of possible beyond the bounds of credulity. This passes as a “mathematical/logical proof” where you live?
In another imaginary possible world where logic, mathematics and the laws of physics do not apply – and not an actual world – I suppose.
And you questioned my idea of necessary metaphysical conditions? Now it makes sense, you require no metaphysical conditions in order to construct a purported “proof.”
The answer would be anything even slightly more stringent than the complete lack of conditions you propose would permit any possible world (like World A or World B) to exist. How about whatever would bring an ‘up’ quark into existence without completely trivializing or nullifying the idea of causal antecedents.
Explicating the necessary and sufficient conditions for anything at all to exist would be a more complete answer.
Feser does as good a job as anyone I’ve read. But, of course you aren’t interested in going that deep in search of an answer, since it is far easier not to require any explanation at all. That way, you can dismiss all attempts at explanation as inadequate, then turn around and propose worlds of single quarks with no explanation at all.