Newbie: Integration with 3rd party UC systems?

Thanks for the response. So, it looks like it is not possible to either initiate a call using a 3rd party UC system from Teams or update status of a a 3rd party call(initiated from outside teams) inside Teams UI. If so, as also asked, is that something in the roadmap?

Is then building a custom tab recommended way to build such an integration that then independently handles 3rd party call control and shows call status?

Thanks again and regards