Sorry for the late reply, had a shitty weekend and couldn't work on anything hacking related.
I got back to it today and applied all the changes (except 23B2: CD 99 3F -> CD A0 FF because that one seems to be the one that changes Samus' palette between transitions). Don't know if this change in particular is the one you meant with this:
EDIT: avoid the last change, it will set the wrong palette for Samus when loading new background tiles.
However, I am still getting the artifact wall that appears when transitioning between areas. All other patches have been applied and everything else aside from the artifact wall between transitions seems to be working okay, though I still have to test out the Ice beam and Queen metroid room.
With that said, if someone is reading this, I am requesting a Save File for Metroid II which is at the very end of the game so I can test the Queen Metroid bug.
I thought I had a 100% file on my Wii U but it seems that one was lost for some reason, so if anyone who is reading this has a save file at the end of the game, please share it so that I can test this faster. It would also help for testing the Ice beam palette as well.