Meaning of eaves side heights?

With this plan, I can almost forget about a usable upper floor :/

Well, now you're exaggerating. The height setting of the eaves here basically just means that no knee wall is desired. Then the ground floor will just be a bit larger, and knee walls will be created in the attic. Of course, you can forget about a "city villa."

Can I submit an application for a change somewhere

No – well, politically maybe, but that's going too far now.

or apply for an exemption permit?

Yes. With the building application. Exemption according to §31 Building Code. It should be well justified, so your designer should think about it carefully. You can also look around the area to see if there are already some existing buildings that obviously do not comply with the development plan. However, if your plot does not have any special features (size, location, height, geometry, ...), the chances are generally low.

With this plan, I can almost forget about a usable upper floor :/

Huh? Don't the other houses there have an upper floor? And if they do... isn't it usable or inhabitable?