There is room to build a facility out to the crossroads for sure, and that would probably encourage some more cycling from residents who live inside the bypass in the SW. However, the big problem is getting through Juniper Green and I can't see how any reasonable facility could ever be built there. It would make the fight over building that school in a park seem like a push over.
Presumably like with most other infrastructure, if you go at a time that is busy with people taking a stroll (Sunday lunch time?) it's a different story, but that's not when you'd expect any real volume of cycle commuters. In winter, the odd time I've tried the WoL I literally had it to myself. There was not one other soul on it, and the adjacent A70 was gridlocked.
Most of the time I am on the WoL I am running, because otherwise I ride on the main road. But I am one of the fraction of a percent who cycle in from the WoL valley. It should be inevitable that the path will be improved as many thousands more houses are built out here, adding thousands more rush hour journeys to the road. But... This Is Edinburgh?