Thanks for reaching out.
We support SSO for both Moodle and Workplace by Facebook using SAML 2.0 SSO.
Your users can login with single credentials into both applications. Also, once the user is logged into one application, user won’t be asked to login 2nd time when accessing 2nd application.
Also, there won’t be any issue with your hosted Moodle setup as you will just have to install our Moodle SSO plugin which won’t require a dedicated server.
Can you tell us how users access (login into) both application today? Also, do you have common users in both apps or some users have access to only one application?
Let me know.