Bulletstop is right, there is a light on the indicator panel that lights up when auto hover is on, it's up and left from the HUD. If you hit control enter to see your control axes you will also have an H show up in the upper right corner there when autohover is on.
It seems pretty typical of everything in this cockpit, if you look at the way the systems interact and where they're laid out it just seems...wrong. Anyone who's had their head buried in the shkval then crane upwards to datalink a target to your friend and immediately afterwards messing with the ABRIS zoom to see your mark knows what I'm talking about. Still, it's part of the magic of flying this thing, and it must not be anywhere near as big of a problem in real life.
I imagine it's a case of iterative design and some serious "hey, I think we've still got some room for something over here!" syndrome :-)