This is really tough, in general Mirroring produces inconsistent ‘handedness’. A part that is mirrored may not be able to manufactured as the same part. Say a mullion cap with a milled out edge.
Rhino flips the Z, which is what actually happens, two parts that if manufactured would not be identical.
Revit uses a Flipped Face Flag, or Handed Flag depending on the element. So the Z remains the same but it internally flips per one Axis of your choosing.
If the Block/Family is conceptual and symmetrical then rotating the Block 180 via the center is recommended, vs mirroring.