I forgot to add:
If you want to work with bits and pieces of a locked down ‘acoustic agent’ kit…
I.E. Use a different snare drum from a different kit…..
Since you can’t just drag things onto empty pads of a locked kit, you’d need to deploy some process to ‘stack kits’, or resample things to build your own user kit.
With full GA, you get 4 slots to host kits at the same time, so you could stack different kits, and use a combination of mute/solo and remapping some of the pads about. Sometimes it’s as easy as muting the snare you don’t want in one kit, and soloing the snare from the other kit.
In Cubase, you can also take advantage of the Drum Mapping feature provided for MIDI tracks, and invoke sounds from GA over different MIDI channels.
If you need to mix and match triggers across completely different GA instances (good for GA SE users who NEED all of the drum kit triggers to be on a SINGLE MIDI or INSTRUMENT track for the sake of the score editor), there’s also a hack you can do to a Cubase Drum Map xml that makes it possible. While this is an older post, dealing with older versions, I think it still works.
Groove agent 4 your own drum kit - Virtual instruments - Steinberg Forums
Note, if you’re not making scores, it’s simpler to just use different tracks for multiple instances, but the XML hack is an ‘option’.