Hello vorvor! Do you speak Hungarian?

If you want to import such a thing you have to follow the import guidelines: https://wiki.openstreetmap.org/wiki/Automated_Edits_code_of_conduct

As you can't really map them from survey as they are not visible.

What is the source of this boundary? Hungarian authorities rarely publish this kind of data with an ODbL compatible license. If you got a special permission you have to publish it here: https://wiki.openstreetmap.org/wiki/Hungary/Importálás/Engedélyek

Please join the Hungarian community on one of our channels, matrix and the mailing list have the most readers: https://wiki.openstreetmap.org/wiki/Hungary/Közösség