Since individual miis always like the same food on any playthrough, should we share our miis to optimize the characters? And if so, where and how would we share them?

Sure, sharing Miis for optimization is good idea. There's a way in the game to make a QR code of a Mii so maybe in the future someone can make a Discord server or a forum post where you can share QR codes. You could also post the Mii to Mii Central under a certain name so other people can find it. Thanks for the suggestion!

i can create the server

Cool, thanks!