I am using supercard DSTwo, not R4, so you can add one more cart issue for the Steven and Mew event..., I also found the issue on it's hex format by using a trainer toolkit, it looks like the whole 0x8000> part is messed and that's where the script data is stored on that event, on the mew freeze event it's not even frozen, I am simply not getting a command that finishes my "interaction" with mew, hope it helps
about the B2W2 hacks you are making and how should you release them - with the approval of ProjectPokemon\PokeStation to use his translated patch- should be released now with a region tag (Pokemon Blaze Black [J].xxx) and when the european and north american versions of the game will get a release and a dump you should simply test it out with your patch, fix bugs and release the patch in a zip file having a folder dedicated for patching with the JAP region and other folders dedicated for the NA\E region, however you shouldn't keep supporting the jap version with updates, since the save file will still sync between J and NA\E games the player can play the game now and switch to a fully translated hack of the game later, an option most of us will choose, hence why you shouldn't focus on the JAP version, that way you get to release the hack, get feedback earlier and improve the game for the bigger release with the international release, the only cons about this method is that you are applying yourself a deadline....