The post of our driveway gate protrudes about 10 cm onto the neighboring property

I wouldn't see it so lightly either, that's not what I mean, but I try not to let it become a tormenting issue that one can't change anyway. Good neighborliness is priceless and if he also recognizes himself as responsible, that would already be very positive for me. Whether I would actually want or believe I should change something, I don't think so. For me, it's always about the how. For me, due to other issues, it has naturally faded into the background... nice plants will then conceal it.

Of course, even a few square meters become more significant with small plots of land. However, the original poster has come to terms with it, and it does not seem to have any impact on the development. Therefore, my suggestion is to keep the ownership rights clear on both sides.