After all, you have a licensed draftsperson who had to deal extensively with the subject at a master craftsman or university level. The employees of the authority are actually only there to check whether the conveyed knowledge is implemented in accordance with the regulations.
Yes, our wishes were discussed by phone with a caseworker of the building authority who gave the impression that this was okay ... but presumably now someone else is authorized to make decisions. And as mentioned, almost all neighbors have exceeded the building boundaries. For us, however, this is not so bad; a "normal mainstream house" is enough for us.