psserver load balancer

Curious as to if anyone has ever placed a load balancer between the web server and app server?  i.e. in the web server configuration.properties file, the psserver string points to a load balancer which then points to the application servers.  This would be to avoid the issue where the web server still sends traffic to a failed application server.  Submitted a SR with oracle and they stated "using a LB here is not recommended... there are instances where  a request needs to be redirected to the same appserver.... for popups with docs where some popup displays a requested doc. This