I reached the conclusion that this storyline could go on forever if I let it and I needed to draw the line somewhere, SO I DID.
Of course, the *REASON* this storyline could go on forever is that there's so many things to address, ranging from exploration of the watches, whether there's new stuff in Nanase and Susan's spellbooks beyond what's been revealed, etc.
In particular, I suspected people were curious about Susan's spellbook. Rather than continue the storyline with an exploration of what may or may not be in there, which would have been more of the same but with just Susan, I decided to simply tease at what she discovered for now. It can be elaborated on at a better time.
Sidenote: Susan is totally in her short, more "hippy" form in this comic. She did get that watch of her own forms, after all.