i learn something new everyday.
john, i know gravel & grind might have a couple of frames. They have some built up so can give you accurate measurements. I test rode their floor model a few months back, it had a 1x drivetrain with sram shifters and i believe 2.8 or 3.0 ranger tires (26") only got to ride it around the pavement around their shop unloaded. some of quick thoughts i remember while riding it:
even though it looked like a monster truck it rode very nice. it accelerated very well with those giant tires, and it was very cushy ride. I thought it would be more relaxed like a traditional touring bike, but it wanted me to push it more and be more aggressive, while still maintaining a pretty relaxed position. remember i rode it unloaded, so those characteristics could very well change with load.
small test ride, but all in all, if you want a rigid bikepacking bike, i would definitely recommend. the ability to fit 26x3 tires on a rigid with disc brakes is awesome. i've come very close to buying it a few times and probably will in the near future.