I genuinely want a chapter that's entirely dedicated to Gaster. I want it to have goofy hijinx and serious moments. Considering who he seems to be related to, it'd suck if Gaster turned out to be way less interesting and humorless compared to Sans and Papyrus.
Give us an entire chapter where the wingle dingle accompanies us so we can really get to know him like any other Undertale and Deltarune character.