THINKING ABOUT MOVING THIS TO THE FUCKING STRUGGLE THREAD, BECAUSE IT'S BEEN A FUCKING STRUGGLE
Now that I know the problem lies with Unity and their licensing model, I tried to purchase their special offer for upgrading to the "new Pro," which has the feature I need, but their billing process triggered fraud protection on my CC, and then proceeded to block all subsequent purchases at my bank.
I just got off the phone from sorting that out with my bank (more difficult than you'd think: meeting US banking hours in Japan), and getting the charges for Unity and every subsequent one cleared.
I go back to the needed email which offers the $75/mo price (same as my current price), and it launches a page that looks identical except it is $125/mo (new price).