A while ago, Stravant made a plugin for reflecting models. However, it wasn’t able to do Unions (and CornerWedgeParts didn’t mirror correctly). With the new engine’s speed and reliability, I figured I could separate all the parts and negate/union them back together, while keeping track of the properties. Works large scale as well.
Be aware: Unions may have random planes. This is due to the negate part’s face being on the same plane as the part. Also, negate parts no longer change the colors. (cc @rbadam)