Thread limit per users in SQUID group?

Question

Squid

There is a group of AgentAccess users with authorization in AD via Kerberos.
It has 10 users.
It is necessary to limit the number of user sessions to 4x.
acl conn_agent maxconn 4
http_access allow AgentAccess auth conn_agent
But this thing applies to the whole group, and when 4 connections are opened, access is cut to all other users. I read the squid manuals, it says that these restrictions are valid only in conjunction with SP authorization and personally for each user. What to do in the case of a group?