Right-click popup access to custom fields

I'm curious if this is already something you can do using the 1Password extension and, either way, what you all think of the idea...

The idea is to extend the right-click popup functionality so it can be used to access any field associated with a particular login, giving you 100% click-n-flill access to custom bits of data for odd forms and tidbits anytime you want, while not changing the way the default behavior works at all: clicking the username itself fills in log-in details; only clicking the expansion arrow gives you the extended functionality.

Note that, in the image below, the box containing PIN, Token, Password, etc., is supposed to be a standard submenu even though it's an open box. It was a quick diagram to get the idea across.