I work in an organization who uses the "Advanced" settings to connect our endpoints to the network. We do not currently do anything with Webex. I am trying to discovery if there is a way to use our VTCs to call into a Microsoft Teams meeting without needing to go through Webex in any form. Especially since trying to access Webex from the Touch10 threatens to erase all of our current settings. So far my searches are coming up as it's not possible. But I wanted to get some additional input before that's what I report back.
Please check with your account team, regarding CMS. I know it has a gateway for Skype for Business; I don't know if it also works with MSFT Teams. But it is an on-prem solution, and you may already have a CMS bridge in your network.