Thank you!
Would you please post a screenshot of the Dashboard and/or Module Admin page messages that you are seeing (as there could be a few different ones in this category) ?
Also, it would be helpful to know your current module mirror situation by sharing the output from this command on your CLI:
$ fwconsole setting MODULE_REPO
Mirror notwithstanding, the terms of the license are covered at Important Documents - Sangoma Technologies as well as other places. Technically, we are continuously adding new models, recently including some Mitel phones popular in the Verticals > Education K12 space: