CHALLENGE:
I'm not good with tools, and don't know what tools are available in the average home shop.
But here is an interesting challenge for you folks that are, especially if you are considering buying a powered skate sharpening machine:
can you use a home shop to improvise your own home-made powered skate sharpening machine? Say, using a power tool to turn an off-the-shelf grinding wheel?
it seems to me you are part-way there. You've created a smooth track for the blade to run through, right? So, if you can find a precision way to align the wheel along the center of the track... Maybe use a drill press, or a drill stand, to adjust the distance??
I suspect the hardest to make component of a powered sharpening machines is the diamond dresser, that grinds the ROH curve across the wheel. One way to do this is to move a diamond tip along a circular trajectory against the wheel, while the wheel turns. The tip could be moved at the end of an adjustable length arm (effective arm length = ROH) - except that the center of rotation is inside the grinding wheel - in fact it is midway through the thickness of the wheel. The obvious way to make that work is that The arm rotates about a center that is offset at right angles to the side of the wheel (typically, the wheel is horizontal, and the rotation center is offset vertically above the wheel; the arm has to be parallel to the shaft the wheel rotates on), and an second extension, at right angles to the arm, holds the diamond point. I think there are other ways of doing that, but I haven't seen them in detail. (I like the idea of using right angles because it is easy to find pre-manufactured items with right angles in them.)
An alternative is to take a sanding or grinding disk, or a mandrill, already shaped to the ROH, so it doesn't need to be dressed at home, and turn it across the bottom of the blade. Cross-ground edges tend to be uneven - but what if you take several runs, turning the disk, etc. in opposite directions on alternate runs, taking very little metal off in the final two runs?
Can you figure out an easy way to make one of these things work, without needing the services of a precision machine shop for working metal?