I'll definitely take a look at this.

What I have in mind isn't really a "proxy" but more of a login/redirection server.

A "proxy" is middleware which directs all communication through a single server which adds to latency.

What I have in mind will run logins through a single server. But once the login is complete, any further communication is redirected to the proper work server to continue without any proxy middleware involved.

This won't entirely eliminate downtime issues but it does limit the effects to a reasonable level while offering increased efficiency and decreased latency.