Yeah this one in particular felt like a weird time capsule for early Saeko & Miwa (to an extreme, since most of these short comics were clearly prioritizing comedy). I think I like "Just Go Out Already!" the most of the pre-serialization doujins because we get to see Saeko act much wiser, and Miwa be much more emotionally open. It's cool that Tamifull-sensei already had that direction planned out.

Oops totally missed that, will fix. She writes “Miwa is an idiot”

It is an alternate timeline, from a doujin that predates the start of the serialized version by a few months, but does have some of the same events that got used in the serialized version later.