I think automations in Ardour are cool, you can automatize pretty much everything, but there are a few things you cannot (or maybe I haven’t found a way, so tell me!).
Send automation: it would be cool to be able to automatize the volume of a send
Mute automation: of course you could use a volume automation as well, but in this way you would be able to control the volume independently from when you want or don’t want that track to play. Starting from that, there is a number of boolean value automations you could add, such as plugin activation, send mute, etc.
Sends cannot be automated yet. There are some surprising issues standing between that, but we will conquer them. Meanwhile, 2.0 is in feature freeze and our focus is on getting it stable enough for a proper beta release.
while mute as such cannot be automated, there is a way to keep the volume control independent of automation which mutes the track/bus. Add a simple amplifier plugin to the track/bus in the appropriate place and automate it’s gain. That way the main gain is not automated and you can control it.