PSD User data fields would be super useful, sometimes I would like to have a field/column labelled "Trigger" that would tell an operator where a trigger is coming from - OSC, MIDI, GO on Eos, analog input...
Other fields could be labelled "Busk", as sometimes my shows require specific busking on top of the GO's and I would like to put a little notice there regarding what busk should be done.
I use user data fields a lot in Concert and it's awesome!