Exclude from Solo

Not at my PC right now, but I believe we just had a discussion and tests about this issue recently.

As long as the send feeding the side chain input is prefader, you can solo the track it is assigned to and still hear it's effect in the track your soloing.

IOW, you don't need to solo two trks.

An exception is virtual instrument tracks, because there's no such thing as "pre-fader" MIDI, and you need the MIDI to drive the instrument.

You don't need a separate function. the pre-fader send option (to create a pre-fader send, simply click on the "post" button so that it's off) is before the solo. Therefore it is not affected by whether it is soloed or not. You bring down the fader for the audio track sending the signal, then it's not heard in the mix but the send still goes to the sidechain.
 
With a virtual instrument, there ar several options but I find the easiest is to render a separate audio track and dedicate that to sidechain control. 

Yes!