I asked about that 3rd line because I also noticed it in the Holeshot product costing twice as much and this guy in the UK told me it was discovered to be unnecessary because the real problem wasn't the need for additional oil, which is really not additional since the path of oil from this third line transits these cam areas anyway, but rather the need of oil being shared by both cams more equally to offset temporary loss of oil from one cam to another due to inertia. Anyway that's what his answer to me was.
I,m not sure that any of the kits do any good, but the oil for the cams comes from the crank area, in the area by the head studs, to he shaft that holds the cam followers, to the cams. The oil that comes though the two line on the back of the engine, though the valve covers, is for cooling the head.
So getting oil from the valve cover is a different source for oil to go to the cams, so if for some reason you are not getting enough oil the regular way, it may help.