you raise an interesting question here with respect to infectious development and pyrocat-hd. Three sources, myself included, on a german b+w forum found that pyrocat good as it is for small formats did not have quite the rendition of fine detail that we saw with something like barry thorntons metol 2-bath or D76h 1+1. Maybe infectious development is the key to this and we should look for a way to control it a bit without affecting the positive aspects of pyrocat to much e.g. good proportional stain.
Presumably there is room for improvement in this direction but I understand that pyrocat was never intended for roll-film formats by Sandy and he will not put much effort into this.