Some ideas that I want to write something for when I find the time and motivation:

Idea 1: Ecolo convinces Abyssal to come to a meeting of the Suzuran High Physics Club, because he wants his friends to meet and be friends with each-other. This also leads to Abyssal finding out that SMG21 enrolled at Suzuran High at some point and joined the club, and she apparently goes by Kira Nadja now. She insists that it's just because enrolling under an acronym and serial number instead of a "real" name would've either been dismissed as a joke or drawn too much attention, but it's clear that she prefers her new name over her official designation.

Idea 2: Sparring match between Commander Valiant and Bandana Waddle Dee, because they've ended up spending a lot of time around each-other thanks to how close Her Majesty and the Great King are, they have not missed how similar their personalities and roles within their respective universes are, and they figure that this would be a good way to get to know one another better and earn each-other's respect.

Idea 3: Cole, Frenzy, and by accident Frenzy's friend Crown the Saphire get dragged along on a Teen Squad Adventure, making them official members of the Teen Squad (whether they like it or not).

Idea 4: While Peony and Doppelganger Arle are doing magic studies the fact that "Pierrot" is actually a stage name comes up in passing and she comes up with "Dapple" as her "real" name on the spot. She plays off the fact that she's been going by Pierrot as thinking that Dapple is too plain for a performer, while Peony reassures her that it sounds lovely.