@they86 - Several features have been added since this initial feature request which really help improve the MOVE and COPY functions in Legend, possibly making this request to “un-mirror” less necessary?
The [[ menu now has options to copy and mirror (in addition to the move that was present before.).
For my use at least, this has made templates super easy. In general, I have not found any cases where I wanted to “convert a mirror to a copy” since the new features were implemented.
So - maybe give the new features a try and see if they meet your need?