Wait, there's an option to host Overleaf locally? Is there any cost associated with this, or any restrictions on the number of users?
[Edit] Found some more info on this, there's a free community version, and then an enterprise version with a fee that lets you self-host but adds features like SSO and support from the company. I'll definitely have to look more into both of these options. Thanks, OP, for making me aware of this!