I am building parts in the context of an assembly.

My document reference triad defaults to the SW convention of Y up.

My master part and assemblies are all Y up.

When I edit a part in the context of an assembly, I agree to suspend the read only status, then the part displays in Y up orientation but the reference triad displays Z up, and when I want to create a vertical line in a vertical plane I must specify horizontal orientation of the line.

Is this what you would expect?