No. I used outdated codes that would randomly freeze when loading the character select screen, but these don't at all.
Mind you, for the minimum codes possible (Warioman doesn't work, at least for me, and the Alloys are garbage), you will not be able to choose the Alloys or Warioman. On the bright side, the random icon will not choose Giga Bowser, Warioman, or the Alloys, so no random freezing. The Alloys will show up as Kirby, Captain Falcon, Mario, and Zelda on the bottom. Just don't choose them (they suck, like I said. No B special, no shield, can't grab the ledges, etc.). Warioman is the Wario icon on the bottom. The only one you'll care about is Giga Bowser, which is the Bowser icon on the bottom row.
You'll also get a Charizard icon, a Squirtle icon, an Ivysaur icon, a Zero Suit Samus icon, and a Sheik icon. The individual Pokemon icons will not have a down special nor will they have to switch, but will also not have a Final Smash unless you choose them through the Trainer icon. And in case you didn't know, the folder to edit Giga Bowser is called "gkoopa".
Anyway, here's the codes I'm using.
I'm using Gecko OS, in case that might make a difference (I don't think so). These are the only NECESSARY codes for using Giga Bowser, if you only care about him. If you really wanna use the Alloys, the only code I think you need to find is the Alloy victory/
pose code, but I deleted it from my code list txt file :x
I'd also suggest using the PSA for Giga Bowser that makes him killable, unless you wanna be on the receiving end of his wrath if you have friends over lol. He's still pretty OP even with the killable PSA, and many times, killing him only minuses a point from him and doesn't give you a plus point.