With PersonAccount enabled, Illuminated Cloud fails to retrieve person account metadata for RecordType changes.
It tries to find PersonAccount RecordType on Account and fails with:
ERROR: Entity of type 'RecordType' named 'Account.PersonAccount' cannot be found.
Rob, IC should just be presenting the metadata types/objects that are enumerated by the server. Have you updated IC's metadata cache since enabling person accounts? I know that can change the metadata shape slightly and I wonder if it's trying to retrieve using dated metadata types/names. You can refresh the metadata cache in either the retrieval dialog or the subscription editor.