It'd prevent them using other Limited cards... Not that that matters, Koa'ki Meiru is the only Deck with a limited card that typically uses Neos Fusion anyway.
Personally, I don't think either card (Bacon Saver or Neos Fusion) is an issue, but eh. Also, Bacon Saver being Limited wouldn't matter that much, cards like Shield Warrior aren't THAT much worse that it'd cripple the deck.
It doesn't work against Gear Golems, and their "spell/traps can't be activated" effect. Bullsh.it if you ask me.
I wasted 2k gems in a Selection Box because I only got 4th copy of everything and NONE OF WHAT I DON'T HAVE, but then in the very last pack I got a copy of this card and it feels like it was a shining UR man.
Pretty degenerate when Neos players use this for an extra free protection.