It's intended for any one user to evaluate ther priors and see how they stack up all together. like that your idea woukd aggregate & have comments & a voting mechanism,
resistance to manipulation can probably come from things like more substantial evidence + personal reputation or identity confirmation.
By the way, why do people weigh zoonotic spillover so high relatively to lab leak accident? There were lab leaks before even in Beijing, eg. of the original SARS when it was researched. That SARS kills faster so it didn't get to infect too many people... And that's only what's documented, considering it's China there could've been any number of other times.
Intentional leak chance is low but accidental leak is so likely it's surprising this pandemic didn't happen before considering security practies that were known and raised questions before the pandemic. But everyone magically forgets about it. All because some US scientists wanted grant money too much and so laughed everyone who disagrees out of the room.
It sounds a little like this RootClaim (I just learned about here) https://www.rootclaim.com/how-rootclaim-works but with the users adjusting & voting on weights?
This is a strawman demonstrator I'm wware of w r t origins probability surveying & calculation. https://www.getguesstimate.com/models/18631
It's intended for any one user to evaluate ther priors and see how they stack up all together. like that your idea woukd aggregate & have comments & a voting mechanism,