Ok, so I think I have found the solution here for 3CX to be able to implement and it should be reasonably straight forward and probably just an update to the core templates and logic.
Currently, the firmware.url = is pointing to
https://server/provisioning/serverid/firmware/yealink/
The actual firmware is sitting in
https://server/provisioning/serverid/firmware_new/yealink/
There isn't a symlink between firmware and firmware_new.
If I query
https://server/provisioning/serverid/firmware_new/yealink/T7X-185.87.0.16.rom the file downloads which is good.
If I manually put the config with the full url to the file, the phone updates.
So it's just a matter of 3CX implementing a setting on the provisioning when the phone does a request, it uses something like the User-Agent "Yealink T73U [VERSION] [MAC]" and if the version is not 3CX compatible, it forces the update.
It just needs to dynamically put the correct URL for firmware based on the Make, Model and MAC.
This way, when converting customers to 3CX, it streamlines the process having to manually touch phones, also the out of box would work with the Yealink RPS as the phone would hit 3CX and get the routerphone firmware and config.
@N_G something you think could be added to the roadmap?
Best
Lance