> If anyone knows where the "I'm happy to control things myself" setting is in Teams, please share.

It's the X button in the top right corner.

In the olden days we had individual developers who would work out the internal API these applications used to work. I wonder if that's still theoretically possible. Surely it must be? Even if the client app needs a signed certificate, since it runs in an unsigned environment (i.e. Linux) it should be possible to grab the certificate and present that when you need it.