Ride what you like!
Nice, Josh! Weird, but nice. Can't wait to see the disk version. Are you planning rear disk as well, or will the brakes be "mulleted" too? I'm thinking about an SS rigid with the double mullet
I setup my TwinSix FSU rigid SS with 29+ F and 27.5 2.6" R sometimes for a bit more cush/lower tubeless pressure/larger volume and to make it a bit easier to roll over gaps. More grippy in the snow too...The Nimble 9 has the option to go 27.5 or 29 F&R. However, I haven't heard anyone try a 29r Front and 27.5 or 27.5+ Rear setup. I was considering the 27.5+ in the rear so I have a larger volume rear tyre.