I guess it's not as much "orienting it in the right direction and then just keeping it that way" as it is a constant to-and-fro - the thrusters are probably not precise enough to keep it oriented towards earth, I imagine the range is extremely narrow by now?

Then the 0.035mm would be a benefit! more puffs!

I clearly have no idea what I'm talking about.

That's a 90 minute cycle time. It's outside the heliosphere now so the Solar winds are no longer a nearly constant force in a single direction. So it experiences more "turbulence."