The big problem at the moment is that currently no manufacturers are willing to supply the OTA files as stand-alone files. Aeon provide stand-along software that includes the binaries inside, but Fibaro will only supply firmware if you use their (very expensive!) hub.
I’ve had discussions with both these manufacturers, and also Qubino - Qubino may be willing to provide firmware, so I’m hopeful that one day all manufacturers will supply these files, and once one or two do, I will look to implement the OTA firmware update class in the binding.