The counterflow exhaust manifold will bolt straight up on the crossflow head, They even use the same exhaust gasket, the 2 liter ports are slightly larger but could be opened still further and remain within the confines of the gasket.
The reason that no one is interested is probably because TT doesn’t make a Syncro exhaust, and would need one of us to send them a complete exhaust to make them. (unless that’s been taken care of already)
I offered to give them a Golf Syncro exhaust and a Passat Syncro Exhaust and they declined both saying “not enough interest in either system in the US”…