I figured that I'd give a quick update on my device registration woes....
After waaay too many emails with support, Twitter DMs to the main Poly account and a supposed escalation, it appears that Obihai support CAN add a device to your account when provided with the "OBI Number," serial number, and MAC address.
Maybe if they had just done that initially instead of me having to prove over and over again that the issues were not on my end but with their seriously FUBAR'd systems....I guess it's easier to put the onus back on the customer rather than using tools that are apparently at their disposal.
If anyone wants to reference it, it was Obi/Poly case 28382150.