I contacted TTC and the reality is less exciting than what their website suggests.? Their reply was "The MOQ for the series is 5 pc. since is a very peculiar R value."
Not sure why my 'any custom value from 250 to 25K' is special.
?
Meanwhile I can find 5ppm parts of 15K and 820 ohm resistors in stock from Digikey for <$5 shipped, and really I just need to be in the range that A2R5 can adjust for so I could just use a single close value vs hitting 15.82K exactly.