Hello
I would like only the Host to be able to modify language, and this should effect all tenants.
What's the best approach to accomplish this?
That's correct, I believe you either have to roll out your own, or wait a few months for Microsoft to port it over. They are targeting to have it released between 1st or 2nd quarter next year.
Personally I may end up building my own, maybe using something like Fire base in the mean time.