Is the variant of very high lift sliding door system statically feasible?

You have 2 options. Take the door as currently planned or pay double the price for your desired solution. No matter what they tell you here. If you have to do it through the builder and they want double, then unfortunately that's how it is. Negotiating is usually not possible, and "but my buddy is a structural engineer and he says it’s not more complicated" won’t help either.

You have 2 options.
Take the door as currently planned. Or pay double the price for your desired solution.

No matter what anyone tells you here. If you have to do it through the developer and they want double, then that's just how it is.
Negotiating is usually not possible and "but my buddy is a structural engineer and he says it's not more complex" won't help either.

Yes, you're probably right, unfortunately that’s how it is. This request won’t help us either, that’s true.
Unfortunately, we are experiencing this for the first time right now.

Thank you for your time and all the answers.

You could take a hinged door on the far left that opens outward, then a fixed part, and then 3 and 4 as proposed by the developer. Such a normal hinged door is much more practical than a sliding door. I would like one instead of a sliding door.

The developer also wants to maintain the symmetry here, so a three-part sliding door system won't work.

Just ask the developer who is paying for the construction, you or him ;-)

A normal revolving door is much more practical than a sliding door.

That is subjective. I'm glad I no longer have a revolving door with the wing always sticking into the room...

I somehow assume it’s about semi-detached houses or similar, hence probably the restrictions regarding a uniform appearance.

Back to the core of the matter: maybe a misunderstanding has arisen somewhere? Your drawing with double frames (i.e. 2 x double lift-and-slide door elements) is indeed structurally questionable, as the stiffening frame must be anchored all around in the masonry. Maybe the builder took the proposal literally and is therefore refusing?

However, you do not need a double frame - lift-and-slide door element divided into four parts, just normal, with the frame only around the outside, opening according to scheme K. This is not used very often, as the actual advantages of the lift-and-slide door are somewhat lost, but basically it is possible without problems.

Alternatively: what about three parts, but not symmetrical? That is, fixed glazing in the middle over the width of 2 elements, and sliding doors on the left and right respectively? Maybe this would still be visually acceptable?