That gizmo has been around for ages- and it never caught on.
If done "right", like the OM's do it, it can work very well.
Ford uses it on their cammer engines, Honda as well, IIRC. Prob. others. But done by an entirely different system hydraulics and ECM, etc.), although the basic principal is similar between them all.
Recently, Comp came out w/a variable timing deal for the Ford OHC that replaces the OEM unit that would (in stock configuration) advance the cam up to like 40 degrees, IIRC.
Problem was, with a healthy aftermarket grind, the valves would get too cozy w/ the pistons. The Comp mods brought this figure down considerably, but still allowed for a lot of degrees of movement. This has to be better than the previous option of eliminating the advance feature all together.