FreeCAD

Maybe there's something I don't understand here. I'd love it if someone told me how to do the following.

Let's say I have some really complex shape in a sketch left of the Y axis: it takes me forever to get it just right. Then I need to mirror it on the right side of the Y axis and connect the two halves.

In SolidWorks, it's trivial: mirror the stuff, done. If you change the master shape on the left, the change is reflected on the right.

In FreeCAD, the best you can do is make a mirror copy of the left-hand side elements - which also makes copies of the constraints which are completely independent from the original constraints on the left-hand side - delete the stupid new right-hand side constraints and slowly, painfully constrain the right-hand side copies to the original left-hand side elements, trying to dodge the dreaded orange over-constraints all the time. It's long, it's painful, and the end-result is usually so fragile that if you change anything significant on the left-hand side, the sketch turns orange and then it's back to hunting broken constraints again.

Surely it can't be that painful. Am I missing something obvious?