You can do this in Sonar, I just tried.I don't mind using the bus method, but that's almost the same as duplicating the track, except you can pach in more tracks into the bus to all be automated at once(if that's the sound you're after).
But, what if let's say I have 3 or 4 tracks, all have some kind of evolving effects that needs to be automated. For example one tracks needs an evolving wahwah effect, another needs evolving compression, another needs evolving phaser...etc. It's be much easier if I can just automate the dry/wet/bypass on the tracks themselves instead of having to create a bunch of buses to cater to each track's automation needs.
I personally think it's really short-sighted of the developers to not have an automation option for dry/wet/bypass.
Insert the effect on the track that you want. Arm the parameter that you want to automate, then you can either move the control in real time or you can draw it in. Then you can copy that same automation to as many tracks as you want. You can also assign that same automation curve to any parameter that your heart desires.

