Your sketches look great. Way better than my chicken scratch hand drafting.

I like the idea of your IO shot with a passive spring based flap; however, I wonder if the ball would lose too much momentum in the horseshoe and opening the spring flip. It would come out, but I think it'll dribble out more than come flying back out to the opposite flipper (or SDTM instead).

It also seems sorta unnecessary. You could arrange the shot more like an "h" shape instead of a horseshoe. So a shot to the left still goes up a ramp, and a shot to the right still comes screaming back. It doesn't seem like shooting it up the left side is supposed to go back out through the right, so why even have the flap? The ball will hug the left side of the rail because of the vector of the shot.

Just my two cents. Definitely need to do some foam core tests to find the right feel on the shot.

Also the ramps are neat, but you may want to consider having a clear plastic ball guide within the walls to help the ball smoothly return instead of clunking around at right angles. Seems like it would slow the ball down too much when the cycletracks need to convey a high sense of speed.