Hi Igor, actually it is not new - publishing a subset schema for an MVD has started a few years ago. Also at that time we made clear, that the subset EXPRESS schema is meant solely for a checker, to run a base check to varify, that the ifc file conforms to the MVD (does not contain additional content). So it is used to formalize the restrictions.
So on your side, you should NOT use the subset schema, but only the EXPRESS schema for IFC4 Add2 TC1. The same EXPRESS schema is used for all MVD implementations.
Remark: yes, the documentation is not very clear about it - something to be improved. I hope, that once we have the fully IFC specification on github, many more people can help to complete the documentation.
mvdXML would be the best way to configure the export (provide a filter that conforms to the MVD). Support for mvdXML is still sparse (and there are some limitations).
Using an MVD specific subset EXPREE file is an alternative way to use it in a parser. As I said before, it is not to parse for your toolbox - here use the combination of IFC4 Add2 TC1 express file and mvdXML.
Side issue - is there a group interested into improving mvdXML (there had been a few initiatives for a binary mvdXML or mvdXML lite)?
You have one candidate here in me. But I think you already know that since I have been talking to @mweise. Would it make sense to create a new topic for this?
@sergej - yes, setting up a new topic is fine - would you go ahead? I assum that also @jonm and @andreas.geiger would be interested and potentially others.
@claimred, I need to fix those links as the domain “www.buildingsmart-tech.org” is no longer valid and the rest of the path is incorrect. I will try to take care of that in the next 24 hours.