Double KFW 297 funding through two residential units?

Hello,
I have just been assigned my building plot and am working on the financing plan for a single-family house to be built. I plan to combine a KFW300 subsidy with the low-interest loan from Bayern LABO.
In a YouTube video, I saw in a comment that someone received two KFW 297 subsidies for their single-family house by having their architect plan two residential units, although the two units are not separated from each other.
What do you think:
Is that realistic?
What would be the requirements? Is there a legal definition of a residential unit? Could an architect still design an attractive single-family house from that?
Thank you!

a single-family house to be built.

So a SINGLE-family house and not a two-family house. Would that even be allowed?

In a YouTube video I saw in a comment that someone received two KFW 297 subsidies for his single-family house by having his architect plan two residential units, but the two residential units are not separated from each other. What do you think: Is that realistic?

As written? No, not possible. Definition of residential unit according to KfW: "Residential units are spaces located in a closed context and intended for permanent residential purposes in residential buildings, which enable the management of a household (own lockable access, rooms, kitchen/kitchenette, and bathroom/WC)." Therefore, you have to build a two-family house. Is the additional effort worth it? Will the new, crappy floor plan then fit? Are you even allowed to build a two-family house? No idea, you have to calculate that. But just the own entrance – which thus requires an external entrance or a proper staircase – would not be worth it to me to subject my house to so many constraints.

That's exactly the exciting part of the question. In the sixties and seventies, there was a tax advantage on houses with a [Einliegerwohnung]. That’s why many houses were built that way. But can you create a somewhat modern layout with it?

There are some who have built pseudo granny flats for the subsidy. This is only partially sensible. A granny flat on the ground floor ruins your floor plan, even if you only create a living cubicle. The space requirement on the ground floor is always quite high anyway, so you notice the missing square meters. It's a bit better with the granny flat in the basement. But building a basement just for the subsidy of the granny flat is an action Pyrrhus would be proud of. The concept can make sense if, for example, you want to move your home office into the granny flat and take advantage of the subsidy by having the connections installed in the basement. Otherwise, it rarely works out financially or in terms of the floor plan.

As always in life, it is possible, but what will it cost? We deliberately built with a [Einliegerwohnung] on the slope, but there are almost no plots of land without a slope around here. We also received double funding. But the construction price for a basement apartment was under 80k euros.

And don't worry, the case workers will definitely keep an eye on your floor plan.

As always in life, it is possible, but what will it cost? We deliberately built with a basement apartment on a slope, but there are almost no plots without a slope here. We also received double funding. But the construction price for a living basement was under 80k euros.

And don't worry, the caseworkers will definitely keep an eye on your floor plan

Yes, that is unfortunately not possible here. Although I had considered it, since the foundation depth of buildings with basements would be within the fluctuation range of the groundwater level, I think it would be too expensive. Therefore, the double structures would only be possible on the ground floor or the upper floor.
The ground floor would have the space problem, the upper floor the staircase problem.