Instance creation page doesn't allow attaching floating IPs if none existed when opened

I needed to create an instance with a floating IP, so I opened the instance creation page in colo. I filled in all of the details, and then realized I forgot to create the floating IP ahead of time. I opened a new tab, created the IP, and then went back to the already opened instance creation page. Unfortunately the "Add floating IP" button was disabled, since when the page was loaded there were indeed no floating IPs. I had to reload the page (and lose the other settings I entered) to be able to add the IP at creation time.

Start at the instance creation page and reproduce the flow: open it with no floating IPs, create one in another tab, then return without reloading. The page should enable the "Add floating IP" button and allow attaching the newly created IP without losing the entered settings.