Is anyone working on a KC-46 model & texture for USAF? There is one hanging out at Boeing Field (KBFI) conducting manufacturer testing. I'm interested in working on flight plans for it, if there is anyone who has done work on the model/texture.

Not that we know of at this time.
The KC-135 models were out of necessity as they were not the same base aircraft as the 707 but the KC-46 is based on the 767-200 and in all likelihood it is somebody that has done that model that is likely to mod it for the tanker version.

In truth this is unlikely until it enters production and in some numbers to make it worth their while.