Global permissions via REST API?

Has anyone found a way to modify global permissions via API calls for Jira Server? We’re running v7.9.0 and need to make a lot of bulk changes to the currently assigned groups. I’ve tested everything on our staging instances (project roles, permission schemes, application roles, etc) and they all work using the REST API but could not find anything regarding the global permissions.

There is a call I can use to retrieve all permission types in Jira including global but there’s no PUT or POST command for making changes. Emailed Atlassian support and they just linked me to the API KB which I’ve already gone through. Their only other suggestion was to post in the developer community…very helpful…