Group policy to set offline files only for all user accounts on a Terminal Server?

Hey all -

We’re spinning up a Windows Server 2019 x64 instance to replace our aging Windows Server 2008 R2 Terminal Server, and FOR THE MOST PART we like to run on-prem and open-source software. Unfortunately, Ubuntu Linux and LibreOffice are anathema to most people, so we have to have Microsoft stuff in our ecosystem so that people can have the familiarity of Windows and Office to do work.

Still, we would prefer to use our Nextcloud instance rather than OneDrive to synchronize our files to a nice cloud interface - is there any way that I can mandate global settings for all users in the desktop clients, via Windows’ built-in Local Group Policy Editor? Specifically, I’d like to make sure that nobody can force download all their files, since their files are going to be downloaded and live on a virtual hard disk.