Is there a way to add a custom unbound field in the designer?

Or better yet, add a aggregate field in the designer. Eg a Total_Cost field which adds the shipping and cost fields?

If not, could it be added to the "Nice to Have" list.

Ian

Not in the Designer, but could be easily added in the generated code. "Using the generated code -> Adding your own code to the generated classes"

It's not in the designer as it's easier added through code than in a designer, as the designer has to make sure that changes of elements in the expression are reflected in the expression itself, and using such an expression in a designer will likely come down to a textual representation, which means a piece of code.