No, the HKParts levers in the link above won't work with the BFS selector shaft. The BFS selector shaft face has a raised half-moon to engage the lever; the HKParts levers engage a narrow raised lug across the middle of the shaft's face. Unfortunately, I can't post a photo to illustrate. IMO, those levers can't be modified for use with the BFS, there would not be a lot of material to engage the shaft and the lever would not be fully supported and stable. If someone proves me wrong, however, I'm not going to complain.
By way of transparency, I'm currently a manager for FA.