If you make two consecutive adjustments in SoftEditSrf, undoing after the command undoes all the transforms performed.
Also, related to many U/V related commands, UV direction needs to be better distinguished when in the command. Simple fix would be, when amending the U distance, to see the red direction markers you would as in RebuildUV >> Direction.
Do you think we will ever see the UI improvement (in other threads I have been part of) where the UVN widget has the letters on the end of the axes? (although, that is less relevant in the case of the Soft Edit where you are only seeing the arrow for the direction you are editing.