aviation is the only business model i can think of where you paid for service/goods and not take delivery of, vendor has so much issue. Loopholes exist for a reason because of pricing logic flaw. I heard many of these "airlines come after you" urban myth but yet to see someone making a scene for getting reprimended for not taking a flight they paid for.

i wont argue arounds ethics or lack of, or pricing logic etc etc as i understand it and exploit them. but OP pls do let us know if you face issues. i would say if CX ever comes after, just say you got sick and your ticket isnt flexible so you chose not to fly.