>You can not use the individual channels in Play you need to set it to Omni to get it working....
I don't have VE Pro5, but I can load multiple instruments into Play in VEPro 4 and assign them different audio outputs and different MIDI channels. Setting any of the instruments' MIDI channels to Omni means it will play all the other instruments' parts.
Maybe I've misunderstood the issue, but a simple test would be to load timpani, cymbal and gong into one instance of Play in VE Pro5, set them to MIDI channels 1, 2 and 3 respectively in the Play GUI (you know how to do that, right?) and then play them individually by selecting the appropriate MIDI transmit channel on your master keyboard.