Click the rig the animation was saved to (note: this currently doesn’t show a selection box - this will be fixed in the future)
Select which animation you would like to mirror
The mirrored animation will be saved as animationName_mirrored, where animationName is the name of the animation you are mirroring.
Request features and post bugs below (NOTE: This is very quick n’ dirty, so please do expect some bugs!)
Moon Animator already provides this functionality, so you could use that plugin. Here’s the tutorial (you should be able to find the info on mirroring here). Getting Started with Moon Animator 2 - [Unofficial]
I’m confused on what you mean by saying “old version.” Maybe there’s a version I haven’t heard of or just forgot about. Should I still refer to an older version or use a different resource?