Easily play groups of instruments at one time during playback

The mixer allows individual instruments to be selected for playback. What I would like (if possible) is for that functionality to be extended to allow groups of instruments to be selected as well. For example - it can be helpful to be able to isolate strings (or woodwinds, or brass) to hear how just those orchestra sections sound without layering in the other sections as well. This can be done today using the mixer, but the process is laborious - each individual part needs to be selected on or off, and then reset again to isolate another section. (It's even worse for string parts, which have three separate lines for each instrument - normal, pizzicato, and tremolo.)

What would help would be the ability to combine instruments into (user defined) groups that could then be turned on and off with one click. For example, a "strings" group for all strings, "brass" for trumpets / trombones / etc., "woodwinds", etc. Making the groups user-definable would allow the composer to isolate individual lines a needed (allowing, for example, an easy way to account for bassoon doubling of a cello line). In this way, it would be very easy to quickly switch back and forth among playback of different orchestra sections, or hearing the entire score with all parts.

Note that this would be in addition to (and not a replacement for) the mixer, as it also is important to be able to isolate individual parts one at a time.