quite a few actually, there's pokemon volt yellow- it follows the anime a bit more but not so much as in ash gray, it's still in it's beta. thunder yellow- you can listen to the original gb music on a gba hack (optionally) this hack is still in development. fire yellow- hm's are cut from this one and i think it is completed v1.
i suppose pokemon let's go pikachu gba can be considered a gba yellow hack. lightning yellow also comes into mind. most of these hacks have some sort of qol or graphical change as a feature, with even fairy typing and gen III mons. there's also @Emerald_boy on reddit making a qol gba yellow hack, nothing, as far as im aware, has been released yet. i'm uncertain about any exp shares in these hacks, though.
