Regarding the ball trap, it seems like you could get some free work out of the lifter posts on the descending side, perhaps they press down a lever in passing that releases the trapped balls?
I am researching at a horizontal spiral loop, I had found out till now, it works only, if the rails are exakt vertical ( "cliffhanging") to avoid energy loss cause of different langth of the rails. The ball accellerates to the middle of the spiral...perhaps it can climb into a plate and than return back to the spiral, but now onto a declining third rail, with leads further... 😊 Just an idea ... I will inform you, when it works.
