2.0 merge files problem?

I was in a locked Scrivening consisting of the 36 files of one folder. In the middle of editing this stream (in the edit window) I wanted to merge three files into one. Wondering if this wonderful new Scrivening environment would let me simply highlight parts of those three files and apply the merge command, I did it. Big mistake, all 36 files got merged. [It is going to be a pain break them apart because 1) the merge is undoable, 2) the print out I have of this Scrivening (done with File > Print) has no file line separators (simple text titles along are not adequate for the job).]

I would suggest that files can only be merged when the focus in on the Binder (I assume that when I was editing the Scrivening in the editor, the files remained highlight in the non-active binder).