Terrace planning for a corner terraced house with a large garden - What to consider?

Get advice first, so they don't revoke your current exceedance.

A preliminary building permit or the subsequent building approval can be legally enforced. Experienced it myself. Withdrawal is the same as revoking an already issued building approval.

I would like to see the response of the building authority.

A preliminary building permit or the resulting building approval can be litigated. Experienced it myself. Withdrawal is the same as revoking an already granted building permit.

Ok. I just feared that a "new" review would result in a "new" factual situation. If that’s safe, the OP has nothing to lose except money.

Small correction: I am allowed to build up to the neighbor's boundary as you wrote that 7x3x2.50 would not be a problem and that you would approve it; 7m is the house width, only the depth is the problem, that you have rejected 4m.

One district over, they don't have them,

Doesn't matter at all. It might be the same in Beijing or Timbuktu. From that, you can derive the same rights as from the district next door.
Right next to me, you also don't have to make an emergency lane on the highway. Here with me, it costs a fine if I don't do it. That's how it is, as was told to the federal government.

The employees of the building authority will hardly make use of their discretion. Because otherwise the next neighbor comes, just like you, and checks what went on with the neighbors.