Very good post indeed, chapeau!
I know some of the Customer's context to which this scenario and the solution apply and find it's useful to say that it works well in an Internet-centric Outlook Anywhere infrastructure, in which all Exchange infrastructure is located in central datacenter(s). The clients in this case connect to EWS from branch offices directly through the Internet, not a company WAN. In a private company WAN with for example MPLS and no internal NAT configurations, the failing load- balancing or resulting RPC connection limits would hardly ever occur (unless the server sizing and scaling is really fubar)
Also, in my opninion, think twice before hard configuring Outlook Anywhere, in the superb service-hacking approach described here, if you are dealing with a large distributed Exchange Org, where DC and Exchange server changes take place frequently.
So with providing solutions i feel it's important to describe the scenarios they apply to a little better, because it better shapes perception.