Incremental mode with null values


I try to substitute all my ddl’s to the models defined in the .yaml files. I try to materialize my models with incremental and the according unique keys.
After compiling I recognized that there is no proper handling with coalesce in case of null values. Is there an option to manipulate the resulting join conditions and introduce coasesce?

The context of why I’m trying to do this

I cant ensure that there arent any null values

What I’ve already tried

Exporting the join to the sql which made it nessesary to create the target table.