Saki interacting with Yu Narukami/Souji Seta more often.

Given that he and Yosuke rescued her, they probably asked Saki how she ended up in the tv world. Since she doesn't want them beating down the door to the police station, not without proof, and getting them all in hot water with Detective Adachi, Saki lies to them.

She's anxious around Yu/Souji because of that lie, so keeps her distance but given he and Yosuke are becoming good friends, chances are they will encounter each other more.

One such thing I imagine is Saki building a one-sided rilvalry with Yu/Souji when she sees him fishing at the Riverbank. The River Guardian is HERS to catch!

Saki talking with Yukiko about various job license possible training classes to take.

At the start of the Priestess social link, Yukiko is looking into career paths for her outside of running the Inn. If she and Saki struck an similar interest in looking over literature and test packages for various careers, I think it'd be cute to see Saki in a supportive role to another girl.

...only for her to experience a twinge of disappointment when Yukiko changes her mind about leaving Inaba and the Inn. Could pick up at any point of this idea tbh, whether tentative budding friendship/mentorship from Saki to Yukiko to distant/awkward when Yukiko decides to stay long term.

Saki going over to Tatsumi Textiles- some time between Kanji being designated as the 'target' via the midnight channel and the resulting stakeouts to just before he's shoved into the tv.

Saki's family business + their house is near the Tatsumi's place, so if the bikers were bothering Kanji's mom, they were ceritantly bothering the Konishi's and their neighbors. Saki would want to thank him for intervening/chasing off the bikers, but would also be intimidated/scared/close to giving into the rumors.

How such an encounter would play out I'd leave to the other writer, since this would be before Kanji faces himself/accepts his Persona.

Naoto and Saki: Similar to Yu/Souji, Saki would be cagey around the Detective Prince, so that could be played with.

Saki talking to Dojima-san after the game timeline. Possibly set before Saki leaves Inaba for good, she'd feel guilty for putting a LOT of blame on Dojima-san for what his partner did to her. So, thinking she'll tie up loose ends, Saki tries to give the Dojima's a letter, only to have Nanako see her and invite her in and/or Dojima seeing her at his gate before he's heading to work.

It just want these two to talk about the events, for some kind of closure to all of that bitterness. Saki won't ever forgive Detective Adachi, but knows that Dojima-san didn't deserve the blame as well.

More interactions with Saki training Teddie on being a good Junes employee. Always welcome more of that! Also, her roping him into pulling harmless office pranks when it gets too dull at work.

Not sure what I'd want Saki to do/talk about with Chie or Rise, but I'm sure there's something.