You don’t have to:

Create a work profile managed by Shelter. then install the sketchy Microsoft app - along with all the other sketchy apps you don’t trust - in the work profile where they won’t have access to any of your important data or contacts, won’t have any permission you don’t want to give them, and where you can freeze them and neuter them completely when they’re not in use.

Here’s a good howto for Shelter and work profiles. Work profiles are great: they’re just as good as separate accounts to keep unstrustworthy apps from accessing data you don’t want them to get at and putting you under surveillance, but they’re a lot more flexible than separate accounts.

Work profiles are a standard Android feature that everybody who cares about privacy should use.