Border design - neighbor wants a fence, we want a hedge

You are right. When planting, they are usually not very large and sprawling yet. After 2-3 years, though, I want to see the one who climbs into the 50cm between the hedge and the fence to trim the side. Of course, that doesn't work. You can only do that from the neighbor's property or you would have to set the hedge back by at least a meter.

The distance also depends on the maximum height, as far as I know. So, for example (I don't have the exact values in mind now) 50cm to 1.5m, 1m to 2m, 1.5m to 3m...

Or I will wait one or two more years and let him plant a hedge. Then I will have space and peace. I find it somewhat unfortunate that the one who comes first also has to bear the disadvantages.

That sounds like a good plan. Since the neighbor has a dog or is planning to get one, it is understandable from his point of view that he first thinks of a fence in particular. I don't think it's wrong if everyone does their own thing, and if he currently has no idea yet, he probably doesn't want to be pressured, which is why I can understand his side as well. Apparently, he means you no harm.

Or set up a relatively high fence on the border (if that is allowed) and have it made opaque with climbing plants.

Cherry laurel is also under criticism because it is toxic to humans (children) and dogs.

Our neighbors also wanted cherry laurel - but that stuff is not coming into my garden. As an alternative, I suggested privet, which they can keep nicely trimmed short on their side, while on our side it stays longer and then blooms beautifully. I would also wait in your place until the neighbor approaches you about the fence; you can share it and that’s that.