how to set "sync across m365" option in powershell/graph or something else

Question

hello, i wrote a little application that automates our onboarding process. it creates a new account in our AD, creates the email account etc. - all worked like a charm, until microsoft decided to introduce this feature:

since then, we have to manually activate that, otherwise the languages are not set correctly. is there any way to programmatically do that, so i can automate it?

i already asked in https://techcommunity.microsoft.com/t5/microsoft-graph/api-for-new-quot-sync-across-microsoft-365-quot-function/m-p/3926050 but never got an answer. this is becoming more and more a PITA.