Do you have the assembly manual? it's probably a cut for a dipstick tube/ oil splash cooler pipe on another model Seeing as our motors have nothing in there I wouldn't worry about it.
I for sure didn't notice anything like that on my build and it's got about 20 miles on it already.
Just make sure you loctite those bolts down that hold it in there.
Currently I have the notch facing the rear of the engine. I couldn't find a picture of it in the manual, but I will look again. I have red loctite on the two stainless steel bolts holding it down.
Just looking my pictures but I think have it going the other way (I can't see the notch). I would just make sure holding down the lifters plates and not interfering/