I thought this had been solved, didn't notice the "low bridge" in oct.
I played too but never posted it. Not 100% done on lengths or line up here.
Adding purple surface, taking from blue. Hide the controls!
Not so much a visual treat didn't try. But more functional version here, with the "pretzel" flipped.
No backing, to get out of the middle loop now. Now full use of both reverse loops, or run 3 separate loops, or some small siding operations.