Jeremy,

I think you are describing an oval with a diagonal reversing track.  Go to my website and scroll down for a picture of this.

https://wiringfordcc.com/track_2.htm#reversing

If this is what you have in mind, it works.  No wiring challenges.

I just need to give you a heads up.  When the train is travelling counter clockwise, you can enter the reversing section going forward and travel to the other side.  But once you have done this and are traveling clockwise, you won't be able to enter the reversing section going forward.  You will need to back through the reversing section to get it turned around and traveling counter clockwise again.

Allan Gartner
Wiring for DCC