As for now , the only format SketchUp reads is .skc, a 'zipped file' containing .xsd scheme files and .xml documents.
check for reference : https://help.sketchup.com/en/article/3000128
While ifc is supported and visible in the Dynamic Component Option dialog, altering the attributes doesn't work properly with Generate Report, yet ?(@Bryceosaurus) . The Uniclass 2015 seems to be a pile of excel sheets ?
Maybe there is a xsd version which you could use in the .skc