Reference System - BIG PAIN... Why?

EP5, SP5 using Logon Tickets.

We've configured our corporate LDAP ids to be "friendly" user names, such as "Jay Brown". Since these ids are not the same in R/3, we looked into the reference system concept. What this delivers is EXACTLY what we need; however, it comes at a huge price that makes no sense to me.

When I map my reference ID to my portal ID through the usermapping interface, the portal will attempt to verify these credentials. Additionally, each time I login to the portal, the portal will verify my credentials with the reference system.

This is a real pain! Why should I have an entire R/3 client that has ALL of out portal users on it? Why can't the Portal issue the ticket based on the fact that the Portal Admin mapped the R/3 id to the Portal id?

- Jay