Getting the best audio and video experiences in Teams with devices

We are now shift from Skype for Buissiness to Teams Direct Routing and earn a lot of trouble. Our Company is an Old Economy Start-UP and we have one year old hardware. With this hardware we have now totally confused our userers because of compatibility issues with Hardware Phones and Headsets. 

So is good to leak about devices which will support in future. But I search a channel where I can discuss in generally the Teams Phone strattegy, because the first thin I do with my trouble, order now Yealink phones for testing and what I see is incompetence of creating software of phones. Yes you can use basic key features but no contacts, no favorites, no meeting PopUp and at lease in Search for Company People you only find the desk number and not for example the mobile number.  I asked our BIG Microsoft Account Teams and the Premier Support only answer was your partner a totally wrong with your adoption.  For me maybe a have to switch ? 

Is there is any experience to discuss this with people who have influence ? The Phone Vendor Poly / Yealink are wrong because of  no feedback !! And Audiocodes told me that they work together with Microsoft :-(.  And have also a Managed Service in place to „replace“ my Partner ? I Search now Influencer of Product group which are willing to give me information because at the end I have to think about my Strategie.

Plesae give me a hint.