For some reason the dot got included in the link - follow the link and then remove the dot and you will get to the folder. https://github.com/Autodesk/revit-ifc/tree/master/Source/IFCExporterUIOverride
I mean, as a guideline, look here: https://github.com/Autodesk/revit-ifc/tree/master/Source/IFCExporterUIOverride. Look for ExportIFC usage.
Look at the UI code - that is what actually calls the exporter (and gets the ExporterIFC class). You are correct that you don't make it yourself.
Please send the problematic file to angel.velez@autodesk.com.
Yes, correct.
You need to get the latest Revit 2023 version from GitHub - it was stabilized after Revit 2023 had initially shipped.
Correct, we export material properties but not for IFC2x3 CV 2.0 because that disallows it.
These discussions have moved to GitHub here:https://github.com/Autodesk/revit-ifc But yes, on upgrade to Revit 2023, we move the IfcExportAs values to the new IFC Export As built-in parameters and no longer use the old ones. Would you want an option that would look at these parameters? We didn't want to do it by default because of the performance cost of looking at obsolete parameters.