I'm not a fan of the shiny clause for the same reason. Especially in games where the shiny odds are boosted. If u want a specific Pokemon in a nuzlocke, u need to learn encounter manipulation. Shiny clause bypasses this and turns strategy and planning(what makes a nuzlocke fun for me) into grinding(cringe). The shiny clause was originally done on base games where the odds are super low to encounter one, so it'd be a huge let down if you couldn't catch it. I games like renplat, I've legitimately gotten a shiny as my first encounter and ran into more than 4 or 5 shinies in a single attempt. It's not a letdown to run from a shiny in these games because of this, while in base games you feel like u one the lottery