The HS shafts are symmetrical.
There is no up or down, or front or back.

When you put it back together, start it up and let it idle for a couple minutes.

If you see a trail of oil running along the head out by the valve cover rail toward the back of the motor, and starting to fill in the area in that rear corner....... and then start to crest(or almost crest) the valve cover rail....... then the oil flow is fine imo.
When there isn’t enough up top, the first thing that happens is the pushrods/adjusters run dry and burn up.
Oil typically doesn’t come spraying out of those rockers when you have the factory “through the cam” oiling.

As I mentioned earlier, the only oil hole is at the underside by the adjuster screw.

With any other rocker I can think of, you’d have more oil flying around since they would have another set of holes either on top of the rocker, or feeding the roller.