Two interesting things that relate I think:
This article about the first HAM radio lightning transaction:
Which relates to Nick Szabo’s https://github.com/GFARadio, which I became interested in a couple of years ago after talking to him at Stanford.
And the coindesk article mentions why Szabo is into the idea of radio network relays, to prevent attacks that partition the network, and they link to this white paper about SABRE: https://nsg.ee.ethz.ch/fileadmin/user_upload/publications/ndss19-final252.pdf
I think incentivizing these type of alternative network relays is centralizing and akin to masternodes, but that doesn’t mean universities and other high rollers or research institutions couldn’t host radio hardware and “super” relays that run parallel to a network to help secure it against (as of yet untried) large-scale attacks out of altruism/etc.
There’s a lot of attacks that haven’t been tested, but that have to be considered for a secure currency, right now blockchain only partially solves the problem. Having what amounts to a mesh network that stores and relays important network information is crucial in the long term I think.
I also think it is even more suitable for grin to consider radio relays since the overally network state should not take up as much space as bitcoin. Actually sending complete layer-one slate files, and syncing the entire chain over radio is much more feasible with grin on paper than bitcoin.