Patch for Per-Request View-Path Additions

A couple days ago I had a discussion here about getting multiple
controller view paths working on a per-request basis. At the end of
the conversation I had developed a failing test for my use case and a
patch that fixes it but I haven't gotten any feedback yet. I am
moving forward aggressively with my app, and the plugin that needs
this new patch, which I think will be useful to many people. I'd love
to get some feedback and +/- so I can finalize the plugin

If anyone is curious what I'm doing with this, I just created the
project plugin and imported the current code at:

So far I haven't gotten feedback about this patch yet. I know we're
all really busy people, but I'm in the process of deploying the
project that requires this patch. If it looks good by the core team
I'd love to have it included. If there's some problem, I need to know
so I can either fix it or just work around the problem the best way I

Does anyone have a few minutes to look at it?