Thanks for the reply! Yes the documentations looks good. Curious to hear if you know of many folks actually using it. Wasn't able to find much beyond the mention on your site and a Bitcointalk forum discussion. Aren't those master fingerprints just derived from the two private keys that you need for signing anyway? Or are those master fingerprints different than the private key fingerprint shown by some devices?

Correct, fingerprint is of the xpub/xprv.