For running multiple MS Teams accounts side by side. Save this with the name of the MS Teams profile you wish to use. When launched, a folder will be created in your user profile. See https://danielsmon.com/2020/04/02/multiple-ms-teams-accounts-on-the-desktop/.

New MS Teams Profile.cmd

@ECHO OFF

REM Uses the file name as the profile name
SET MSTEAMS_PROFILE=%~n0
ECHO - Using profile "%MSTEAMS_PROFILE%"

SET "OLD_USERPROFILE=%USERPROFILE%"
SET "USERPROFILE=%LOCALAPPDATA%\Microsoft\Teams\CustomProfiles\%MSTEAMS_PROFILE%"

REM Ensure there is a downloads folder to avoid error described at
REM https://gist.github.com/DanielSmon/cc3fa072857f0272257a5fd451768c3a
mkdir "%LOCALAPPDATA%\Microsoft\Teams\CustomProfiles\%MSTEAMS_PROFILE%\Downloads"

REM Fixes missing "Desktop" folder
mkdir "%LOCALAPPDATA%\Microsoft\Teams\CustomProfiles\%MSTEAMS_PROFILE%\Desktop"

ECHO - Launching MS Teams with profile %MSTEAMS_PROFILE%
cd "%OLD_USERPROFILE%\AppData\Local\Microsoft\Teams"
"%OLD_USERPROFILE%\AppData\Local\Microsoft\Teams\Update.exe" --processStart "Teams.exe"

Hey @jmakowet, sorry I don't have a clear solution for you. Hopefully someone else might be able to chime in. I haven't had a need for this for some time, and it seems that the way MS Teams works has changed since I set this up. If it still works, it may be an option.

Otherwise, have you tried simply connecting one via the web and one via desktop? The only thing I'm not sure about is whether it would let you join with the same account, or whether you'd need multiple. Good luck!