Thanks for the questions.
Hauptwerk has two, distinct combination action systems with general and divisional pistons. One is Hauptwerk's native one. This is the one that you see on the toolbars and the large floating control panels. The other one is the one supplied (sometimes) by the sample set creator. Those you see on the virtual consoles and extra screens provided with the sample set.
Only Hauptwerk's native combination action automatically outputs the last piston pressed information via the status port. Those messages automatically come up on the LCD screen when it's connected.
You can make the pistons from the sample set send messages too. However, you have to program them to do so. We made the screens so that you could have those work with those pistons if you do the setup inside Hauptwerk.
Here's a tutorial on how to do it.
Programming "Gen" and "Comb" to work with a sample set's combinations.
Unfortunately, the backlighting is not adjustable on these.
This is a MIDI device rather than a USB device. So, it's compatible with either Mac or PC. So, there are no driver issues.
Does that help?
Darryl