After quite a bit of research, I found these American Classic 26 Tubeless wheels, under 1500g a pair!
I thought the white rims and red anodized hubs would go nicely with the already brightly colored Mojo (nuclear pesto). More importantly, a recommendation from my engineer friend John sealed the deal - apparently the rear hub pawls engage via a friction plate, meaning the hub is going to engage even when gunked up, perhaps even better than clean!
Add smooth, 23mm deep, aerodynamic rims and two white spokes pointing to the tube valve, tubeless compatibility, all resulting in a bling looking wheels. The cassette mounted with a spacer and the disc brakes needed just a minimum amount of adjustment.
The real world test was done under totally unscientific conditions (new environment, no direct comparison, no objective measures etc.) on the Tahoe Rim Trail between 7500 and 8500 feet of elevation. Whatever the beneficial effect of 250 grams less of rotating mass over my old wheels, it was all lost due to my physical struggle on the first day. However, the second day of riding included a fast downhill on pretty technical rocky trails, and I can confidently say that the wheels felt totally stiff and solid, and in combination with my tried Schwalbe Nobby Nics greatly tolerated all my piloting errors. Nice job, Bill Shook!