Stretched Split Phantom C/L/W/Boxes

This is analogous to the Stretched <anysetup> concept. In a setup in which one might use a Split Phantom formation concept, the center two of the four subsetups move past each other as they start the call, and finish in the Split Phantom formations.

\syhBBBBs{.+.,g2w,.+.,b4w,g1e,.+.,b3e,.+.} \syvBBBs{b2w,g4w,.+.,.+.,g1w,b3w}
+ + 2 4 + + 4 2 1 3 + + 3 1 + + 2 4 4 2 + + + + 1 3 3 1
before Stretched Split Phantom Columns Track 2 after