@Anne and Greg, thank you both for chiming in. Certainly a bit for us to mull over

as a follow up, would I be able to run 650b wheels on 700c CX frames? Probably a dumb question, but just wanted to confirm.

Another option would be to get a hardtail MTB and put drop bars on it. I seem to recall there are some rather light hardtails out there (approaching 20lbs)