This is certainly a simple gear. There is no doubt it is lighter and less involved to build than the standard XL gear assembly, the unknown is how robust it will be in the field. Landing loads with the plane aligned with the runway centerline should be accommodated as well as with the standard gear. Sideloads are the question mark--this gear may be best suited for the experienced pilot who is less likely to fly the XL to an...ah...arrival.
I'm debating replacing the axle crosstube with a single length of 3/4" x .059 instead of the 5/8" x .035. The 5/8" tubing has some flex and heavy side loading will load the tube in compression which in an extreme case could lead to buckling and loss of integrity of the entire system. The weight tradeoff would be slight, yield a stiffer assembly and lower the parts count even more.
On the other hand, this is the classic conundrum of figuring out how much strength to build into a design. We can't design a very lightweight aircraft to survive unreasonable punishment, we just want it to be strong and light enough to absorb routine operating loads. XL-58 will be flown by a pilot with over twelve-hundred tailwheel hours; consequently, design considerations are different than would be the case for a primary trainer. The standard XL gear is certainly satisfactory and proven, this is merely an exercise in trying to make a simple design even simpler without compromising the strength of the plane.