Hi, i think a nice suggestion would be to make Shiny Charm obtainable in game.
Shiny hunting is one of the most favorite part of pokemon games for many players. I know that it is nice to keep shinies rare, but we could make shiny charm extremely difficult to obtain, like catching all the legendary available (through World Quest), or have at least 1000 hours gameplay.
In order not to ruin the game and fill it with shinies, the Shiny Charm can give 1/5000 chances instead of 1/8000, which is still pretty rare.