So, let's say I am designing a weldment that has two lugs symmetric to a centerline. I make a plate for the lug, then mirror component to get the lug on the other side. I'd like a mate to define the distance between the lugs, yielding a dimension that can be inserted on the drawing. In Solidworks 2021 sp2, it seems impossible to create such a mate; I have to resort to some workaround. Perhaps a third lug mated distance from the first, as an envelope in the assembly.

I'm curious about how anybody else might have been in a similar scenario and how you solved it. Thanks in advance for sharing!