Thanks for your thoughts. Looks like I have 2 options.

(1) Mount hard case on rear rack. Thanks for your suggestions. Looks marginally feasible: exceeds rear rack weight limit, likely to require extra bracketing (not a problem).

(2) Get a trailer and then put the hard case on the trailer. The funny thing is - I need to also check the trailer! Seems like the the only bombproof strategy (i fly 100 times a year) is to get another hard case for the trailer. That’s 2 hard cases and a trailer....that can fit in a hard case! The only one I see is the Burley Travoy. I get 2 free checked bags each flight so this seems OK from a recurring cost perspective. 2 20lb cases on the Travoy means I could carry an additional 20 lbs. Seems to fit.

Fortunately, I can try (1) and then migrate to (2). The extra $500 (case + trailer) seems better than having to buy a new bike every 20 flights!!!

I will report back with my findings. Any additional thoughts are appreciated.