Unlisted-distribution approval is a separate, lighter check than the public App Store review, so having it doesn't mean 4.3(a) will clear on its own resubmitting the identical build usually just repeats the same rejection (another commenter here did exactly that and got a warning about repeated submissions). Since Resolution Center has gone quiet, the App Review Board request form citing the unlisted-distribution approval date as evidence the app itself was reviewed and cleared is the more reliable next step than resubmitting unchanged.

Sorry to hear it went to Extended Review that queue runs up to ~90 days per Apple's own SLA, so the silence isn't unusual yet, just slow. One thing worth checking before the next round: 4.3(a) "same feature set" often gets triggered by how the App Store listing reads (screenshots, description, category) as much as the binary if the Turbulence and Price Tracker features aren't front-and-center in your screenshots/description yet, the listing can still read like a generic flight tracker even though the code changed. Worth updating the listing to lead with what's actually unique, and citing that specific listing language in your Resolution Center reply.

Rebuilding does not change what 4.3(a) is comparing: the outside of the binary and the listing, not your code. Three things that usually clear it: (1) make sure the bundle id and CFBundleName are your own brand, not a placeholder like com.example / com.anonymous / the template's name; (2) delete template demo screens and starter assets that are still in the bundle; (3) in the Resolution Center reply, name one verifiable feature that no other app in the category has and where to tap to see it — "our app is unique" gets ignored, a specific tap path gets read. If the second review still says 4.3(a), appeal with the same specifics; those do succeed when the app is original.