Are the semantic representations produced by grammars implemented with the MATRIX fully compatible with the current ERG semantic representation documented in ErgSemantics · delph-in/docs Wiki · GitHub? If not, what is the differences?
There are surely differences, in many cases the Matrix is lagging behind the ERG (e.g. in the representation of coordination). In other cases, the decisions documents in the ERS pages might be specific to English constructions or involve constructions not handled in the Matrix. I do not have a complete catalogue for you.