Are you aware of any software supporting import/export of Linear Referencing data in GML version 3.3 format?
Apparently no software application, proprietary or FOSS, currently supports it explicitly. I've read elsewhere that "GML 3.3 is itself a GML 3.2.1 application schema". So maybe software applications that support version 3.2.1 already implicitly support GML 3.3. Yet that does not necessarily mean the correct bindings for LRS reading/writing have actually been implemented. Please let me know otherwise.