ᐅ Vapor retarder in the attic: Should it be installed all the way up to the roof ridge?

Hello everyone,
we are in the process of adding new insulation to our roof in order to convert the entire attic into a living space.
In the sketch, I have outlined our plan.
We would like to install the insulation material up to the roof ridge (green lines).
Directly behind that, the vapor barrier membrane would be installed. The membrane should also extend up to the roof ridge. Since we have cross beams, the membrane would need to be cut, which involves a lot of effort. Because the future ceiling of the apartment will only reach up to the blue line, our idea was to apply the membrane not up to the roof ridge but along the red lines. If we are allowed and able to do it this way, we would hardly need to cut the membrane in this area. If this is acceptable, we would also install additional insulation (yellow line).
Our question once again: can we install the vapor barrier membrane (red line) in this way, or does the membrane have to be installed all the way to the roof ridge?
If you need any further information, please let us know.

Thank you all.
Best regards

Since the final ceiling will be along the blue line, you don’t need to insulate the ridge.
This means you don’t have to extend the membrane all the way to the roof peak, only up to the "blue" line.
However, I would recommend installing boarding above (yellow line) to prevent the insulation from being compressed.