I thought I had the Smart tool figured out after completely unlearning my PRV surgical editing techniques from pre-X1 days and relearning them X1-style, but of course it changed again in X2.  

I simply want to be able to hit ALT-3 after clicking to set the "now time"  of a midi track to bring up that track's note data in a Full PRV screen.  Whenever I do this, it always comes up with every single event in that clip and/or track selected.  There was a lengthy discussion of this back in X1 as well.  No one could come up with any scenario where you would want everything selected in PRV by default, and yet it persists.

I finally figured out that I could right-click with the smart tool in a blank area to unselect everything, but this step seems unnecessary.  Is there a way to change the default behavior?

Double click on the clip or don't select the clip but put the track in focus and press Alt+3

Yeah, the only time all notes are selected for me is when the clip itself is selected, so like Karl says, you just need to select the track in the track pane if you're using the key combo to open PRV. Otherwise, just double-click on the clip and it won't matter if the clip is selected.

Thanks guys - that is very helpful.  I was trying to nail the coordinates by single clicking near the offending event, which selected the clip itself.

It will take a little practice - my double click action is set for staff view, but I might change it to PRV to get the ability to get the "Now" and open PRV in a single action (Double click).  

The key to the other method is just focusing on the track (not clicking on the track number which selects everything in the track) and then using the CTRL+ arrow keys instead of the mouse click to locate the right spot horizontally before using the ALT-3 command.  

Of course, to view multiple tracks in the same PRV, you do have to select the clips or tracks and the right click to deselect is a good option to mass unselect them.

If it helps you can set the now time by clicking in the time ruler then use the Alt+3 shortcut for the in focus track to open the PRV at the now time.