Re ISM band usefulness: yeah. I grudgingly admit that the propagation characteristics of HF and probably even VHF aren't a great match for the ISM governance model, but at least everywhere I've ever used radios, UHF HAM bands are as dead as a doornail and don't (fine, generally) propagate far enough for small numbers of negligent users to create major problems for large amounts of users. Take some 400mhz UHF and make it ISM. 902-928mhz ISM has a ton of great stuff like LoRa going on, but access to 400mhz bands would be a huge shot in the arm to the practical usability of projects like Meshtastic without significant risks to the general usability of that chunk of spectrum. Another interesting thing about the history of protocol development in ISM bands is how the need to cope with noise/overuse/other forms of spectrum degradation has spurred enormous advances in encoding and signal-processing techniques, quite contrary to the initial expectation of useless garbage dumping zone bands.