Ah, you already have an upstand.
Don't have a better idea than get rid and replace with dekton all the way up.
Maybe you can repurpose the 10cm strip somewhere else?
Ah it's in one piece with the worktop?
You could chose a different colour of tekton for the wall, use the thin stuff and use some sheet material to make it the same thickness, and make the different colour a feature?
Ah, you already have an upstand.
Don't have a better idea than get rid and replace with dekton all the way up.
Maybe you can repurpose the 10cm strip somewhere else?