This topic came up when we were doing the original IFR kickback for $vectorSearch-on-a-view. It would've been nice for the vector search extension to be responsible for uasserting/tasserting based on the value of the vector search extension feature flag so that we didn't have to hard-code "is-extension-$vectorSearch?" checks in the server code.

To do this, we would need to figure out how to throw IFRFlagRetry from an extension. We would also need to figure out how to communicate about server feature flags over the Extensions API (since the IFR toggle logic is defined in the server and the extension wants to reference the server's feature flag).