The solution:
And the permalink:
https://www.lodev.org/jstumble/?board=rlerrf0lfaglflafrrrfrilfrlferfeerf
By abusing the fact that the puzzle puts no constraints on the balls in the bottom tray, we can avoid the crossover and just feed the red ball directly into the gear bit (similar to my solution to puzzle 19). If the initial configuration is right-right, this will cause one red ball to reach the bottom before the second red ball gets caught in the interceptor. The caveat of this is that this is not as easily reusable as a generic XOR gate for later puzzles (where we might not be able to afford a stray ball in the bottom tray).
For a βcleanβ solution which always intercepts the first red ball, we can still save a few parts over the reference solution by joining the two paths to the red level earlier (resulting in 23 parts):
And the permalink:
https://www.lodev.org/jstumble/?board=rrerelee0rfaglleelaleerrxfrilfrlferfeerf