If you are trying to download firmware from EPM server then you can see logs in “fwconsole debug” which will tell you about downloading progress and download is purely depends on size of firmware and your internet speed.
If you dont find anything in log and stuck forever then i think as you are using commercial module so request you to please open a commercial support ticket here
I was answering the first part in regards to the firmware download failing.
But, Yes, there are other ways to get the firmware in there.
Whether today or 5 months ago, if there is an issue with the firmware downloading from the Sangoma repository then he should most likely put in a ticket as @kgupta1 and myself mentioned.
But, thank you for answering the second part, as the new way to input custom firmware was not something I knew about.