You can target the following powershell below to update items in desktop-config.json such as 

disableGpu\openAtLogin\registerAsIMProvider\runningOnClose

(Get-Content $ENV:APPDATA\Microsoft\Teams\desktop-config.json).replace(‘”disableGpu”:false’, ‘”disableGpu”:true’) | Set-Content $ENV:APPDATA\Microsoft\Teams\desktop-config.json
(Get-Content $ENV:APPDATA\Microsoft\Teams\desktop-config.json).replace(‘”openAtLogin”:true’, ‘”openAtLogin”:false’) | Set-Content $ENV:APPDATA\Microsoft\Teams\desktop-config.json