I don’t think there is such a limit, but more a case of the available RAM on the system.
Autodesk said it improved workability for model up to 1Gb with the recent version, but in general it is better to keep the Revit files below that (800 Mb)
That’s without external files, of course.
If you do not have access to Revit, one can create a project in Trimble Connect for Desktop and add the Revit file.
Then create a view and select only what you need in SketchUp and export that as a TrimBIM file.
Though the organization is slightly different, one can come up with a workable file in SketchUp.
Check this thread about another Autodesk format: