I feel you, I actually get quite a lot of joy out of the edges that the KO3 gives, I can get some good edges freehand, but they're not as quick/consistent/symmetrical/repeatable as things on the KO3. I don't have the glass stones, but do have the Shapton splash/go stones, and diamond plates - I just slowly raise the spine of the knife as I'm on the back stroke, and push downwards on the forward stroke (freehand).
As for the convex lens - I have the new one with all the micro-adjustments, but it just showed up and is still in the bag, so not sure there - for the standard convex lens, I have tried both the 7.2° and 10.7°, and prefer the 10.7° convex - as shown in their videos, lower the stone all the way down on the knife to set your angle, I likely went a bit shallow for the A1X, but it was removing enough sharpie for my liking, which was, if I recall, 19.5° (or so), and then did the standard sharpening, but before you move to the next stone, you'll do micro strokes, at the top of the rod stroke (again, its in one of their videos). This worked well enough to get an edge that was sharper than factory, but it wasn't what I'd call factory convexity, as it only went up the blade ~1.5mm or so. Hopefully this is helpful, I can go take photos of what I did as well, just let me know.