Ideas for a GF Lost Legends sequel or well midquel.
1). We get a story that features Ford working together with Dipper and Multi-Bear!
We learn more of their friendship and their interests.
Multi-Bear meets Ford! Him, Multi-Bear, and Dipper become an unlikely trio!
They all work together to find something or someone in The Crawlspace about Ford's past. Maybe also some information of The Oracle!
Also maybe some more flashbacks of Ford's childhood and maybe Multi-Bear shares some of his childhood memories too.
Also their love of the group BABBA and their hit song Disco Girl!
2). The second story can be about Pacifica working at Greasy's Diner.
After her parents lost their mansion for pledging their alliance to Bill. Pacifica has to find work to pay off her parents new house.
While at the start, she's her usually bratty and spoiled self. She slowly learns how to be nice and compassionate to others. Also because her, and her parents aren't wealthy anymore, no one is cowering before her.
Even when Pacifica is mean to her at first, Lazy Susan is is still cheerful and polite towards her, she even lets her stay at her place when her parents are "busy" wallowing in pity.
We also learn a little bit of Lazy Susan's past and why she's nice. Also her becoming Pacifica's grandmother figure.
3). A reconcile story of Old Man McGucket and his son.
We get flashbacks of what's his childhood like and what type of people his family were.
His friendship with Stanford, him giving an axolotl, and more of their friendship during college.
Some flashbacks of him when he was healthier, and his relationship with his son Tate McGucket, along with is ex wife Emma-May.
Maybe even some tension between Ford and Tate for understandable reasons.
4). A story of Wendy during high school, and still having adventures after The Pines Family left Gravity Falls.
She's still the awesome laid-back, rebellious teenager, we know and love, but this time we learn a bit more about her childhood and who her mom was.
We see the relationship between her dad, her younger brothers, and her mom before her disappearance (I like to think she disappeared when Wendy was twelve. Also I believe in this theory)
In the flashbacks, we get to see her dad training her and her brothers for an apocalypse, and her awesome fighting skills!
The origin on how she met Tambry, despite being complete opposites. Also her eventual friendships with Nate, Lee, Robbie, and Thompson.
We also see she still goes on adventures without Soos and The Pines Family. Sometimes she goes on adventures with her friends or brothers.
Maybe even while she's ditching school during a boring trip at the museum, she finds a something about her missing mom.