Makes sense. They keep claiming Skype for Business is dead, but Teams in my opinion is very far away from being a realistic replacement.

I've not been very impressed with the desktop application at all (although the web-site is "fine").

I have deployed teams in 'island' mode for our org and I'm a bit disappointed with it - we've had firewall problems with external attendees and have had to switch back to skype for that case. A few users have had the teams client crash repeatedly during calls. I don't see how anyone will move to it with issues like these.

Could you encapsulate these dependencies into a separate service? I did that a while ago in a similar situation but as always it depends on your specific situation.