I se a lot of different ways to look at this, and a lot of different situations, I guess. I used to know this little queer club in the Detroit area where a couple straight women were regulars. They were lovely, kind, everyone's friend, and ... rare.

The club (more of a large bar, really, with a modest dance floor in a separate room) was often packed, and these two women usually seemed to be the only cis/straight people around.

It felt as if they'd adopted an element of our queer community as their chosen friend group, or maybe something like family.

Of course, they honored the implicit rules you spelled out.

I doubt anybody objected to their presence. It's not as if they were tourists out for an evening of gawking or flirting with queer folks.

I'd be surprised if they made anybody significantly uncomfortable.

But I wouldn't be surprised if an influx of straight tourists would turn club goers off, supposing that increasing numbers would inevitably result in more inappropriate behavior.

It's an open question, I guess, to me.
I think that defaulting to a hard ban on cis/straight people in queer clubs can't be the best answer. But neither can letting queer clubs be overrun by non-queer guests.

The devil's in the details, as is so often the case!