Is it possible to show the loop size for Decks C and D (instead of A and B) in the center displays on the Z2?
Did you have a look at the Controller Manager? It seems like you have some flexibility on how you can organize some mappings, but I'm no expert here.
https://support.native-instruments.com/hc/en-us/articles/209590569-How-to-Use-the-Controller-Manager-in-TRAKTOR
The Loop Size display on Z2 and X1 MK2 is not overmappable in default mapping mode unfortunately.
It does work in MIDI Mode. and you will be able to display 0 to 127 if I'm not mistaken.
I will have a play with this and see if I can assign specific midi output values to match at cc1, 2, 4, 8, 16, and 32 at least. Didnt think about that. Thank you.