I have to say that modern VVT timing engines also depend on all of the factors that you mention regarding oil. Once an engine gets to temp it is going to be very consistent just at the new cars are unless the oil degrades or the passages get clogged. The spring thig is real but it won't change daily. You will get what you get and I don't see rocker ratio being an issue in any way. New cams come with enough lift that even down .025 they will exceed stock 2 barrel cams.
Like I said. I'm running a set on my 273 with a 213 @ .050 cam and it pulls over 21" of vacuum at idle. If the 273 don't struggle down low I don't see how a 360 would.
But it's a theory and I'm trying to gather the things needed to test it. The thing about Rhoads is if you don't want the vvt affect you just adjust them like a normal lifter with zero lash. This is also a great way to test the effects of the lifters themselves. I have driven my car with zero lash and then adjusted it to .025 then driven it again in the same day. Guess which setting idles smoother, has more low end torque and gets better mileage?