Just because they paint in broad strokes doesn't mean everyone should turn their head off. That is how you get people calling everything full lockdown. By discussing with local doctors one can create a protocol for this that has low risk. Why shouldn't a Rov follow that? They can be careless about these protocols when it comes to the Peaceful Protests that are important to them while we can keep to low risk manners of breaking the heilige protocols for what is important to us. Keeping to protocols when the risk is so low is a losing argument. You (and I) keep saying that people should use their heads and not just ignore everything they are told just because some incompetent made crazy rules. This is the flip side of it.
As an aside, I was on the phone with the Chair of Epidemiology at a local hospital who was asked about keeping mikvaos open. He said that he did not see an issue because it was such a brief exposure it was very low risk. For these people to go outside with masks is even lower.
A very big problem exists when you tell/show people that all the rules are meaningless - and yes even COVID+ can even come to shul. People come to their own conclusions and decide what is safe based on some thoroughly debunked article from the Washington Examiner as we've seen time and again during corona. In a vacuum, the decision to have a COVID+ minyan isn't the worst idea; in a community where you teach everyone to disobey the rules, it's a terrible idea.
You still haven't described a medical need for it.
Putting COVID+ with COVID exposed is a medically stupid idea. Even putting exposed with other exposed is not smart. You justify it by comparing to the risk of shuls where we've already convinced everyone to show up without masks, but I don't think we need to compound our mistakes.