Ableton Forum

This is the only thing that's better about using an MPC (with JJ OS) than the Ableton drum rack - you can select all of a particular parameter in a drum kit and change, say, every attack at once, or every pitch env amount at once, or select just half the pads and do the same thing. Yes, there are macros in Ableton, but the useful thing about this is that it's immediate and temporary. Maybe shift-clicking multiple slots could allow you to edit them all at once? It might not always make sense, since you can have different types of devices, but I'm sure there could be a way to detect if you're selecting the same thing or not.

Alternatively - this is also MPC-inspired - why not have a way to highlight multiple parameters in a single device, then option-drag that device into another slot, and instead of the whole thing being copied, only those parameters are copied onto whatever's in that slot already. ie if you had two pads with Simplers, you could edit the envelopes on one and copy onto another without overwriting the start and loop points.

edit - I finally discovered right-click + "Copy value to siblings", that helps a lot