Can I not automate a send plug in?

Curious. I'm trying to write automation for a delay feedback, but it doesn't seem to work. Is automation not possible for plug ins?

Automation for plugins is possible, but only for normal tracks and semi for audio tracks but not for the sub busses, return busses and master busses.
It's kind of frustrating if your song needs this (I know).

Please hit the feature request button in the software and request this feature. I've done so as well.

According to Pete this feature is still on a boat somewhere in the Bermuda Triangle.