I think Viv is just terrible at writing romantic relationships, whether they be hetero or homo. Moxxie and Millie was cute and wholesome at first, but became boring real quick, mostly due to the fact that Millie is a nothing character. We can see why Moxxie loves Millie and wants to be with her, but we don't know why or what Millie loves about Moxxie. Same goes for Ozzie and Fizz, who started out as an interesting dynamic, but immediately by they're next appearance became sanitized. Ozzie's character now solely relys on Fizz, and Fizz was woobified.
Same goes for her building up relationships. Stolas and Blitzø could have worked if there was proper buildup to them falling for one another. But that requires effort and skill, so it's better to gaslight the audience that they have always loved each other, they're just terrible at communicating it, and this relationship wasn't solely built on transactional fucking. Angel Dust and Husk are most likely going to end up together, even though there's no logical reason why they should. No chemistry beforehand, with Husk being especially annoyed with Angel Dust, only to have one scene where they go out of character to randomly start caring about each other.
So, could Charlie and Vaggie work as a lesbian relationship? I'd say yes. But only if Vaggie became her own character, we get good reasons for why they would love each other, interactions between them that builds on their relationship dynamic, and a competent director that knows what the fuck they are doing.