Trail Chain Thru

This is just a Peel Chain Thru, but the outsides do a Cross Cast Back instead of a Cast Back.

\syhDBDs{g1w,b4e,g2w,b1e} \syhlines{b2n,g2s,b3n,g3s}
1 3 4 2 2 4 1 3 2 4 2 4 3 1 3 1
before Trail Chain Thru after


The timing is rather awkward, so the original center 2 need to wait before doing the Fan the Top.