A few questions about modifying the KBR1:
Thank you
These changes will require serious firmware modifications. I think if you need specific features that interact with the mtag216 chip in the xNT then you’ll want to develop some software for the acr122u reader… easier to work with than the omnikey.
Can I ask, what’s the purpose? Do you need HID keyboard output or are you aiming to integrate your own software into a specific project?
I would ideally like to output as long of a value as possible for use as a password, but the serial number (I believe is the xx:xx:xx:xx:xx:xx:xx value?) is not editable and so I could never change the output value.
I would also like to use the scanner in a professional environment and the audible ‘beep’ when scanning is slightly distracting. Would actually like to buy one unbranded if possible as well (the sticker is on my car FWIW lol).
Any plans for a companion software to make the above changes at some point? How about a black Friday sale so I can buy 2 and keep the 2nd at work? 
I should clarify that if I did have the ability to output a specific records value when scanning the xnt I would start looking for ways to build an application around it
The issue with reading tag contents is that getting the UID is part of the ISO14443 select process, but reading specific memory contents is chip-specific, so it would only work with specific chips with specific memory structures and command sets, and doing chip detection and all that is quite a pain compared to just outputting the UID.
You can open the kbr1 and remove the buzzer or just cover in layers of tape to quiet it down quite significantly.
Is the UID the ‘xx:xx:xx:xx:xx:xx:xx’ serial number value in NFC tools?
Yep, though displayed differently.