Many thanks for the input - yes, I can see where you're going with this.

In the final analysis, I have a button on the toolbar for the tracks window
and then it's just one more click on the solo button and a click to close
the window again.

When I'm mixing, I tend to bring in each instrument in turn, using the solo
function. In a typical mix I might have 20+ tracks on solo, so three clicks
is still going to be much easier than de-selecting each track separately.

Thanks again,
ROG.