Is high ceiling height possible with controlled residential ventilation?

For our single-family house, we would like high ceilings (270cm). However, I would also like a controlled residential ventilation system in the house. Now I have just been told that with a controlled residential ventilation system, I either have to lower the ceiling by 15-20cm or plan the controlled residential ventilation system into the concrete ceiling. If we lower the ceiling by 20cm and want a ceiling height of 270cm, we have to plan for high ceilings from the start. Due to the development plan (max. exterior wall height 450cm), we would then have a very small knee wall on the 1st floor. With the controlled residential ventilation system in the concrete ceiling, I can no longer lower the ceiling and would have to also plan the lamps (spots) into the ceiling. Somehow, I don't like that. Are there other options with controlled residential ventilation?

Wall and floor outlets (*brrr*)

And of course, you can still hang the ceiling with controlled residential ventilation in the concrete ceiling - for example, I have (planned) that in the kitchen.

I am not sure yet if I can come to terms with floor outlets. The question then is whether wall outlets "are any good". According to the architect, that doesn't work if you hang the ceiling afterwards, as it then does not allow air to pass through.

Great architect...

The valve naturally extends into the suspended ceiling.

Oh man, you are right. I wouldn’t have thought of that now either. ops: Plan controlled residential ventilation in the concrete ceiling, hang the ceiling "normally" and extend the outlets so that they are in the suspended ceiling. Is the controlled residential ventilation in the concrete ceiling something that is often and standardly done, or so unusual and difficult that it becomes expensive?

With controlled residential ventilation in the concrete ceiling, I can no longer suspend the ceiling and would therefore have to plan the lamps (spots) in the ceiling.

What speaks against it?