This is a very important point. I have found that on occasion keys got corrupted or something else happened which required some kind of auth with the upstream Particle cloud. It would be good to get guarantees about this serviceability into the future.
I had similar thoughts. Thanks for articulating this so clearly. The mesh is very important to a core group of us, and while technically BLE might be able to satisfy our need we really don’t want to reinvent the wheel. If Particle can commit to minimum support to keep Xenons alive and kicking in their current form, and perhaps have a small lib so that <=v1.6 can still effortlessly communicate via BLE with >v1.6 that might provide 99% of the functionality for 1% of the effort.