I appreciate ur work on MMDVM, but I am not sure abt ur statement:
For example, DMR is originally not open and fully documented. Some things have been reverse engeneered. We all mostly use MotoTrbo Tier2, which is fully proprietary of Motorola (even with Hytera radios) and also your MMDVM is using a VOCODER-chip (AMBE), that you need to buy and use in hardware in order to have a license for it. So I cannot see any difference to Lora at all. So also Lora is fully documented and you can buy chipset for 433MHz very very cheap! So why not using it?
73 de Mike