red or black lines
[ATTACH alt="Teilungsplan.png" type="full"]58802[/ATTACH] a little image correction can also be done with paint.net.
larger context
[ATTACH alt="Luftbild_Flurstück.png" type="full"]58803[/ATTACH]
If I were one of these two, I would first "consolidate land" and swap 1055 and 1056 with each other (even without compensation for the 28 sqm).
Not necessary, it is residential building land secured by a rounding statute according to §34 Building Code.
but all too large for single-family houses
No, Hinterland development does not allow the statute.