I just picked up a used Z1 which doesn't have any software to replace my Audio 2 MK1 as a portable rig that will work with TDJ as well as TPRO. Currently, I have 3 serials on my NI account related to Traktor:

TRAKTOR LE Audio 2 DJ
TRAKTOR LE 2 TRAKTOR AUDIO 2
TRAKTOR PRO 2 Upgrade

All of these were from a year ago and I went through the extremely tedious process of registering each of them, and then submitting for the appropriate upgrade.

I'm wanting to sell off the Audio 2 and understand about the EULA regarding hardware-specific serials. That being said, it only appears to me that LE and LE2 are hardware specific, as the Pro 2 upgrade was from before they stopped giving everyone with unregistered NI hardware an upgrade to Pro. Currently NI offers for new hardware purchases a $50 e-voucher to upgrade to Pro.

Can I de-register the LE and LE2 serials and keep my Pro license functional for use with the Z1? This seems the easiest route as it will keep the hardware-specific serials attached to the Audio 2 for resale. However, the process has gotten extremely convoluted and I'm not sure what the best course of action would be to take here.