your notes on upgrades are superb and very comprehensive. They do omit however the CIP code which I always get put in my booking. I think this aids with moves from PE TO UC especially ex:UK. It's effectively a corporate imp. person code. It doesn't guarantee anything but it can help...worth talking to travel agent if you work for company which does a large spend on Virgin.
I have to admit my knowledge of the CIP codes are thin, to say the least. I'm guessing from your message that this can be entered by the travel agent at the GDS level, rather than a Virgin agent-only code (like SFU - Suitable For Upgrade).
Pix