this hack is excellent! i guess the third gen is just very conducive to great hacks, between this and radical red lol. a few bugs i'd like to quickly note:
1: knock off still removes items when the target has a substitute up. if im not mistaken, this behavior is inherited from the base gen 3 engine, but i dont play enough competitive adv to have been in that situation to know for sure. very minor bug, and honestly its an interesting quirk so i wouldnt blame you if you decided to leave it in on purpose.
2: ultra necrozium z, or whatever the z crystal that lets necrozma-duskmane and -dawnwings ultra burst, does not seem to work at all. having it equipped on a necrozma dusk mane with photon geyser did not allow me to use the z or transform into ultra necrozma.
3: the z crystals and mega stones seem to be a little bit bugged as well. i had a situation happen where i clicked z-hurricane with a noivern, but died before it went off. when i switched into my salamence holding salamencite and clicked the mega button, instead, it fired off a flying z move and didnt mega. i was able to mega the following turn. this one is also honestly pretty cool and a neat gen 1 esque sort of bug that i quite like, wouldnt mind it staying but it is still a bug.
4: the safari zone does not seem to handle "combo" pokemon correctly. ive found so far both a necrozma dusk mane and a calyrex shadow rider. ive gotten base necrozma to appear, but both dusk mane and dawn wings fail to do so. as for calyrex, no form is spawning, even the base form.
5: im not sure if im doing something wrong, but even with max happiness, i cant seem to evolve riolu at any time of day. ive tried morning, evening, night, and the middle of the day to no avail. again maybe im just missing something tho lmao
misc extremely minor things ive noticed: catching a morelull for the first time shows its shiny coloration on the pokedex screen, even if it is regular. also, catching any regional variant of any pokemon in the wild results in all variants appearing in the safari zone, i.e catching alolan sandshrew on an adventure gives you both kanto sandshrew and alolan sandshrew in the safari zone. very possible that this was done on purpose, and if so, disregard lol
all in all, an incredible hack. super appreciate the increased shiny odds too, if i wanted to hunt real shinies i can go play a real pokemon game. but sometimes i just wanna use a shiny altaria lmao. its very obvious how much care went into it and im having a blast playing it. sorry if anything ive said sounds too harsh, my pointing out the handful of minor bugs ive noticed is not a condemnation or criticism or anything lol. i personally just like when people point out bugs in my code so i can fix them haha. i eagerly await both more updates to this hack and any future hacks you make <]:^)