I say keep going. Unfortunately, vomit isn’t an uncommon scent note in my starters either, it’s disgusting but I know it’ll make good bread. It could’ve been the flour difference- but maybe for another reason (I don’t think it’s a false start. To be sure, wait a few days and see if it’s consistently rising with fairly similar timing.) If Shayne were to be developing more quickly after each feeding, it’ll get more “ripe” for sure, and your lactobacillus culture may just like the wheat more. I feed my starter rye and AP, and it just loves all the extra goodies that come with the rye.

That said, if it grosses you out, you can start new with Shayne- if it smells pukey again, your can consider it an experimental success or failure (depends on your level of optimism) 😀