... I fucking hate to answer this but Asterion's poolside costume (and all new outfits for him) will have to wait for the next update.
Full disclosure: we stumbled a bit with planning this update, we had all of the content written for Kota's hangout scenes when we announced the release date, with a "conclusion" to Kota's arc eventually getting added to chapter 19. About a month ago we realized this was not a great idea, people already have massive blue balls from us taking a six month break and doing side stuff while all the threads from chapter 18 are still dangling, so we decided to give it a shot and use the rest of the month to write and add this to the game. Nemo ended up being a gigachad and writing 11k words of additional material to give this side story a really satisfying conclusion, with the entire team pitching in to edit.
As for the R&D stuff we were planning to add, I, uh... went a little crazy and wrote 10k words for the pool scene. And since A) I'm not a native speaker, B) not as experienced a writer as the rest of the team, and C) I wrote the whole thing over 3 days in a fucking frenzy, it needs a lot of editing. We'll most likely split it into three R&D projects, even. And we're stretched a little thin with the Kota stuff, so we'll be moving it to 0.6.1.
Sorry for the disappointment, but I guess the good news is you guys are getting more content than originally planned and even though we promised we'd make small updates we still made a really meaty one.
*another bit of good news is that since everyone's busy editing I have the time to do stuff like redo Ismael's sprites and add a couple really big quality of life updates we'll be revealing next week.