i wonder how you use the reverb with GPO.
i see two possible way of operating:
1) you assign every instrument to its separate ASIO ouput (ex. violin on ASIO 1, celli on ASIO 2, etc), and create a single audio track for every instrument. in this case case you can use the reverb on a aux channel and decide how much reverbered should be the single track.
2) you simply put a reverb on the main output of GPO and all the intruments of that instance are processed equally by that single reverb (with no control of the amount of reverberated signal on a particular instrument) - of course in this case i'm speaking about a single GPO instance. with two or more instances you should use aux send...
for now i have always used 1), but i see 2) is much more simpler. i wonder if it is a realistic and correct way of operating... (certaily it's easier!)
this two way of working also raises to me a question about mixing:
in the case 1) you have full and easy control of the volume of each separate track in your mixer.
in the case 2) you either mix "inside" GPO, by changing the track volume in the single GPO slot, or you use the expression (CC1) to get the "right" dynamic of a single instrument in a particular passage.
related to this topic, i wonder also if the volume of the single GPO instruments are setted in such a way the single instrument reflects the real dynamic and volume of that instrument in the real orchestra... in that case, you should just use CC1 for mixing....