I used to freelance for a big corp who used MS teams and provided me with separate credentials, while also having my private MS account, that I occasionally use for other corps I worked for.

It was a hell using it that way. I had to run each one in a private Brave window to be able to work on two different accounts.

I know they only use MS teams, bc their infra is all based on MS, and it probably works fine for them internally. But man, this shit needs to be fixed in some way to account for external people, especially the ones who chose their own stack and work simultaneously with others.