Eclipsa, there will be flashback about why she escaped for the monster dick and of course interaction with Star and shit.
Tom mostly for the leak with Star, flashback or not, they still need to stray Starco, but not only that, there will be episode with him and Marco for sure, and of course exploration of what is the underground kingdom.
PH is like Nefcy child, of course there will be an ep about her, that probably gonna be about her kingdom.
I dunno what i can expect about Toffee after his keikaku was literally recover his finger, but maybe something related about the lizards?
Jackie, if she just gonna be Marco gf just to make Star jealous then you can't expect much more about her, i would consider her Oskar tier at this point.
Janna, i dunno, an explanation of why she likes dark stuff and why she is really interested in Marco maybe.
And of course, lots of hugs between the two besties.