On that trip (Red Sea, Dec. 2017) I ended up doing what I proposed in that thread: putting the drysuit into a big clear plastic bag that has no closures, and then packing that in my regular roller duffel. I bought a flat-bottomed bag made of relatively thick (4 mil?) plastic--nice and sturdy. For extra padding/protection, I packed the plastic bag with the drysuit in the middle layer of the roller duffel, between some clothes on the bottom and clothes on the top. I don't think TSA removed it, but if they had, they probably would have put it back in the bag. The system is certainly not impervious to punctures, but between the roller duffel and the plastic bag I think it would resist a lot of abuse.
Even more awkward than the drysuit itself were the drysuit hangers we brought along. We didn't want to hang the suits on the thin (metal?) wetsuit hangers that the liveaboard would inevitably have. Despite the bulk, I think bringing the hangers was a wise decision.