Microsoft Teams Desktop client - Proxy settings

In my company we (the IT-Administrators) use Microsoft Teams for planning our projects, scheduling meetings and as a general chatroom for work related stuff.

Due to other applications in our organization we need to connect to a third party proxy server which requires login credentials for those specific programs. That proxy connection inherits a very restricted bandwidth and content, so in our Admin space we use our own way more performant proxy for those applications that don't need a connection to the third party proxy.

Because we need to set the system default proxy to the third party one, Teams always wants the login credentials and the upload and download bandwidth is highly restricted.

I've searched through the settings but can't find any to set a seperate Proxy within Microsoft Teams.

Is this just straight impossible without changing the system wide proxy or is there a way to change this which I'm not seeing? (Besides using the web based app)