2 questions on for performance and user Identification

So I have a self hosted jitsi server setup.
Currently running on a VM with 4 vCPUs and 4GB of memory.
We have about 15 people on a call at a time. Is that enough CPU and memory?

Second part is I have LDAP configured for login to the conferences. Some users show up as “Fellow Jittster”, others have “does this chat work” the rest show with the userID from LDAP is there a way to make it so it always reads the userID from LDAP when they log in?