Spork 1.2 has a single threaded mount / eyelet just above the thru axle which was intended for a lightweight front rack, but is commonly used to mount fenders or racks with larger mounting plates. There isn’t a huge amount of space between the threaded mount and the thru axle hardware, so these spacers effectively move the mounting face farther outboard to clear the thru axle. Made of stainless steel, they’re thin-wall for clearance and unthreaded.
Spork 1.2 ships with a pair of these spacers but they can be ordered separately here if needed.
Dimensions are 5mm length, 7mm O.D., in case you’d prefer to source or make your own.