Building an end terraced house - Which technical requirements should be considered?

Yes. Not the lot itself, of course, but the declaration of intent "I am applying for plot 10" should be supplemented with "... and would like to build with Huber" or "... and join the choice of the executing guildsmen of my row".

And what is the office supposed to do with that? The criteria are clearly defined by the city before the start as to how the selection is made. And if you deviate from that even slightly (because then you make the result contestable), you will always have someone disadvantaged who will take action against it.

your considerations are all well and good, but you don’t seriously believe that the OP can now go to their municipality with this and they will change it because of that? It’s more likely that the Pope will have twins and open the BER together with them.

The plots will be allocated according to the procedure, the problems will then be addressed afterward.

In practice, either building permits will only be granted if it more or less fits, or the municipality really doesn’t care and some of the housing groups will be a bit more heterogeneous than one would expect.

Technically, all of this is solvable.
Just go to any old town and see what can be connected to what.
Sure, it’s not always trivial and can lead to problem areas in the long run, but that doesn’t make such projects impossible by any means.

Apart from the vulnerability of the procurement system itself, I consider it legally more than questionable if the municipality now simply quickly selects a few companies with which building is "allowed". As a company not selected, I would be grateful and seriously consider legal action.

[*]House groups in the open design require an adjustment in the type and extent of the annex as well as in the design similar to the semi-detached house, see the explanations on this.

[*]Coordination with the neighboring property owner(s) is necessary for the boundary annex. Depending on the situation, an obligation to attach or even an annex building encumbrance may be required.
[*]The regulation may give rise to a neighboring defensive claim.

pulled from the WWW... Bau-Rat de
In Plankstadt, there will later be small print to read:
Builders of house groups must adapt to the first construction of a house group in DN, WH, and GH

Köhler & Klett also included current case law on the topic of house groups and open design in its December 2015 newsletter.

In Plankstadt, there will later be fine print to read:
Builders of the house groups must adapt to the first construction of a house group in DN, WH, and GH

Excerpt from a 2017 ruling:

The overall appearance of a harmonious whole does not require that the individual houses must be constructed identically. A uniform overall structure can still exist even if it is loosened up by smaller offsets and setbacks (BayVGH ruling of 9.2.1999 – 14 B 96.2272; ruling of 11.12.2014 – 2 BV 13.789, confirmed by BVerwG ruling of 14.09.2014, 4 B 16/15). The individual buildings must be connected to each other quantitatively – to a substantial extent – and qualitatively – in a mutually compatible and harmonious manner, which must be assessed based on the specific circumstances of each individual case. Quantitatively, this especially considers the number of floors, building height, building depth and width as well as the above-ground gross volume essentially defined by these dimensions. Qualitatively, factors such as roof design and the other cubature of the building matter (BayVGH 11.12.2014 op.cit.). Taking into account the dimensions of the other terraced houses, the width difference of 2.00 m to 2.25 m, or only on the north side 2.46 m to 2.96 m, is quantitatively not of such significance that a uniform overall structure would no longer exist, especially since both the end-of-terrace house situation and the fact that the western end-of-terrace house has a width of 12 m on the south side due to the extension must be considered. The owners of the terraced middle houses, often located on significantly narrower middle plots, cannot demand that the same widths be realized in the larger end area as are only possible on the smaller plots. Rather, it is often precisely the wider end-of-terrace houses that harmoniously complete the overall appearance. Regarding the heights, there is only a marginal offset at the ridge, which is unproblematic in view of the allowable offsets mentioned above. The same applies to the objection that the southern outer wall is 1.24 m deeper than the neighboring one. An offset of this depth is already unproblematic per se applying the principles set out above.

Or is the expectation that someone here will familiarize themselves with YOUR development plan and explain it to you?

I complain in countless threads that you can do little to nothing with fragments from development plans, that the overall context always has to be seen, and now a thread starter comes along who provides complete information right from the start and that is too much? If you want to give a useful answer, then you have to read everything. Some formulations are simply difficult to interpret for inexperienced people (sometimes even for experts). And if he only quoted parts from the planning law provisions, there might still be passages in the design-related building code part that are important for answering the initial question.

Perhaps will find the crucial passage in the plan.

I cannot contribute anything new to the initial question, but can only confirm that the municipality wants to restrict the freedom of individual builders as little as possible.

So, I will NOT look into the development plan.

Then don’t. But then you should also refrain from such posts:

In Plankstadt there will be some fine print to read later: Builders of the house groups must adapt to the first construction of a house group in DN, WH and GH

Where is that fine print supposed to be? There is a legally binding development plan with an integrated design statute. The approval authority cannot invent additional criteria that could prevent a regulation-compliant building project. For that, an amendment to the development plan would have to be initiated with all consequences (public hearing, public inspection, council resolution). The justification for the development plan clarifies the concept of building freedom IMHO even more: 6.3 ... The individual decision-making freedom of individual builders is restricted to a reasonable extent in favor of an urban-planning desired mixture ratio of house types. ... 6.11.1 ... By grading according to plot sizes, owners and prospective builders are enabled the greatest possible design freedom on their own plots. ... 7 ... The provisions on the structural execution of the main buildings (roof shape, roof pitch, roof structures, roofing) shall ensure an acceptable overall appearance of the new development area while allowing sufficient scope for individual solutions. I can understand the concerns regarding technical difficulties and the overall appearance, but I cannot see any reprehensible conduct on the part of the municipality. The Legoland villages of the resettlement sites in the Rhenish lignite mining area are partly not exactly pearls of urban planning either, so I quite welcome a different urban development approach.