Hi @agron, the issue you are experiencing about using very high numbers as a way of georeferencing is because the geoferencing entity in IFC is missing. Indeed, any 3d format with large numbers will have parsing issues.
The solution, and proper way to georeference in IFC is to use a map conversion, along with a target CRS (coordinate reference system) entity. Therefore all of the local coordinates will be nice and small and manageable.
I have written about how georeferencing works (and gotten it checked by John Mitchell at buildingSMART, who invented the entity and is a domain expert) here:
It is an unfortunate scenario that programs like Revit don’t understand how to properly do georeferencing and that leads to misunderstandings, such as people offsetting their entire model to absurd distances. (Note that offsetting is actually incorrect, as proper local to global CRS conversions have other transformations too, such as scale, also. Different sites on a large project will each have different transformations)
If you’d like to play with software that supports IFC georeferencing properly, you can use ArchiCAD, FreeCAD, or BlenderBIM. If you are stuck with Revit, I highly advise you reset your coordinates to the origin (I show how Revit calculates coordinates in my post) and enter in georeferencing data manually into the IFC file (it’s not hard), or if using IFC2x3, put it into a separate metadata file.