Ah, yes, the UI (Flash-based in the cases I mentioned!) is definitely clunky, so it's not surprising Capital One's is similar. They also tend to hide the feature a little bit for some reason; it's not prominently displayed. But otherwise it's there and nevertheless usable if you can find it. If you need it on literally a daily basis, though, it might not be smooth enough to be comfortable.

Could you MITM the extension to reverse engineer the API calls it makes and write a command line tool to perform the required functions?

I have a friend at CapOne, I’ll ask tomorrow.