What do you think, would the airframe be a write-off?

Hard to tell....

Would the USAF do this or just eject as the safer, although more expensive
option?

Really depends on the type of aircraft. That flat belly on the Tornado makes
it a natural for a safe belly landing with minimum fuel onboard. Don't
believe anyone would try that on an F-16, the bird would almost certainly
roll over.

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José Herculano