is it possible to export gpx data for a specific area per (anonymous) user? e.g. not one file with all data, but a set wich distinguishs between the different contributions?
No. At the moment you can either get all the dots in an area fully anonymised, or a get an individual track file.
There’s been some privacy stumbling blocks but Matt’s recently (in the past week) developed some new features which may go live very soon