Do tall doors fit a "normal" room height?

because otherwise he always ends up with some of the expensive special formats left over. [...] He has a saw anyway. I want to say that a complete layer of half bricks will be much more expensive for him than a layer of regular bricks.

The height compensation bricks would not exist if they were indisputably uneconomical compared to sawing them yourself. They are needed regularly and can also be stored in containers, so next week there will be some from the previous construction project again ;-) No contractor would think of using the jumbo format taking three NF steps at once alone, and therefore being able to vary floor heights only in 25-cm steps. Being able to lay three layers at once is good - but it is not a quantum leap.

Important also, pay attention to the quality of the doors!!

What does good quality mean? The plan is doors with tubular core panels (If I am not mixing up the term, I don't have the list here at the moment). But we will decide when we see and "feel" the doors.