[itsme]

I use transpose to have a song in more than one key sometimes permanently: I copy the song in collection "line-up A", transpose the copy, change the collection of the copy to "line-up B", change the key in the song editor to the new key and keep both copies (that refer to the same CordPro file).

The other use case is the one that you mentioned here, changing the key during a jam temporarily. The issue that the transposing is saved, and resetting it later to the intended key can easily be forgotten has been discussed before, e.g. here:
https://zubersoft.com/mobilesheets/forum...=transpose

A workaround exists already: just create a collection "Temporarily Transposed" and add the songs. Then make a copy of the song and add the copy to that collection before transposing it. (edited)
A shortcut to do that without having to open the song editor is discussed here:
https://zubersoft.com/mobilesheets/forum...2#pid28782