The models are specifically listed within the Yealink template of EPM (which I assumed to mean were supported/made available by the ‘3rd Party Phones addon’). Not only that, EPM enables me to configure REST-Apps for these specific handsets on Line/Soft keys no problem. I’ve also been using the Parking & Voicmail apps & they all appear to work just fine. Also, I believe all the T5 series use a unified firmware & so it stands to reason (I guess) that they should offer similar feature support/functionality.
The only missing link is that the T5 expansion is not supported, even though it uses the exact same underlying config entries as the supported T4 expansion, which makes no sense to me as to why it wouldn’t be made available (but that’s a whole other issue I guess).
I appreciate your assistance, do you have any suggestions regarding the ‘Dial from Contacts PhoneApp’ issue ?
PS. Support for these Handsets to be recognised as ‘Certified Devices’ within EPM v15.0.39+ was officially announced in Dec-2020 (see Endpoint Manager - Addition of new Yealink endpoints).