Use batch requests to modify Google Drive permissions
Changing Google Drive permissions across ~30 drives has been shown to be quite slow (especially given we may be changing permissions for ~1000 users, looking at how many users some colleges have added so far). Tested with staging, changing 5 user permissions across all drives took ~2 minutes (so for 1000 users, we'd be looking at several hours).
To reduce the impact of this, we can combine permission changes into batch requests (see the Google documentation on using batch requests).