Get your Teams launcher v1.0 binary from here.

New in version 1.0: Fix for "Download -folder missing" problem, new icons.

Project files and other source code is located @ https://github.com/loukkis/win-2nd-teams-instance-launcher

Teams launcher is a tool for launching 2^nd instance of Microsoft Teams client in Windows easily.
If you need to run two Teams clients simultaneously with second account or with the same account, this tool is THE solution for you.  

I Hope that Microsoft implements real solution soon, so you don’t have to use gum & glue solutions like this, but until then...

It is free, and it’s safe, I swear!

.Net Framework 4.7.2 might be needed on older Windows.

It is not signed application, so your computer might nag about it. No installer, no need for admin rights. Just unzip the file, run it, and click Launch! for 2^nd instance of Teams client!

 If you too find it useful (I did, that’s why I coded it), follow me on Twitter and just say thanks, that is more than enough for hard 3 hour time that I have used in this. https://twitter.com/loukkis