Currently, if you hold down "a", "{STATE_KEYSTATE:a}" will return "1" as long as it's physically held down. However, if you have VoiceAttack send an "a" keypress, "{STATE_KEYSTATE:a}" will return "0", as VoiceAttack sent a key release.
For certain commands, it would be useful to have a way to get the last known state of the physical key, to check whether it's still held down.
I believe this used to be possible (I.E. "{STATE_KEYSTATE:}" returned the last known physical value regardless of VoiceAttack's output), but it was changed at some point.