Jobu Tupaki's eccentric and wildly confusing costume, as well as entire being, represents not only the generational and cultural divide of assimilating into American culture, but it also represents her queerness and "fatness" that is confounding to Evelyn. Her daughter is alien in orientation and culture, and might as well be as unreadable as her outfits. Her daughter being in control and having power is too an evil that must be defeated.
I also read the insanity of the multiverse as
1) traveling through Evelyn and her family's identities and 2) existing in the modern times. For the first point, jumping through the multiverses showed the path that could've been--in China and other realities. These possibilities are also as confusing as the taxes Evelyn has to fill out. All of these directly tie into their ethnic and national identities, existing as an immigrant family in America. Additionally, to me, the relentless influx of information and possibilities speaks to the digital worlds we live in. The pace is unsustainable and incomprehensible. Thus, the thread between self, community, and national identities meld together into a big, disorienting metaworld.