Ceiling cornice ideas pls

[neoT]

Hi,
Our house have a curved/rounded wall where the staircase to the 2nd floor is.
The cornice of the ceiling at this curved wall is problematic.
The current cornice was done by cutting the cornice into short lengths(50mm) and then stitching them together to form/follow the curve, but it looks crap.

The ceiling needs to be replaced due to water damage and the contractor wants to follow a similar approach as the original - I don't want this, I want it to look a bit better/neater, but neither me or the contractor can come up with a workable idea.

Polystyrene cornices doesn't want to follow the curve when you bend it - I have tested it.

Some ideas from the community will be appreciated.

[pclouwrens]

This company sells flexible ceiling cornice.

https://www.nmcsa.co.za/cornices/