I hc that every once in a while, whenever he begins to lose his humanity, when he loses his sanity just a bit too much Dipper travels through time, contacts past Alcor and they make an agreement. The Dipper that travelled gets to experience a day of where he travelled to, he can do whatever he likes, whether it be in the early days with Mabel, with the triplets, with Toby, with Lionel, whoever. The Alcor experiencing that moment normally answers all summons for the day making sure the traveller gets the full experience.
He never changes anything, he just makes their day happier.
When he has to leave he cries for days but is sound in the knowledge some part of his humanity survives, he’s going to be okay.
backup 