While looking at
#965 Christian Reisswig and I noticed that Carpet seems to call the routines on the finest level whenever any recompose happened. This is ok to ensure that global (also global-late) routines are called but also means that local routines are called. In cases where the finest level did not actually change (happens in core collapses we believe), this causes unnecessary calls to eg. MoL_PostStep with its attending SYNC calls. This might be candidate for optimization.