I think if I was to redo Smash's take on custom moves, I'd design them exclusively and explicitly for casual play - those base 4 special moves make up a solid fighting character with strengths and weaknesses, but the alternate versions are crazy source material fanservice that isn't really balanced or based on a playstyle - made for button mashers and lovers of busy screens above all - for example, Captain Falcon jumping into a Blue Falcon to ram it into foes and explode, doesn't fit his playstyle, and there aren't many downsides to just lingering in the seat, but it's cool and nostalgic so here it is in the customs. That way the "he did the thing" crowd is statisfied, but competitive or just attentive players used/attached to the old movesets are satisfied too. A lot of Ultimate and to a lesser extent 3DS/Wii U's newcomers would probably have their default specials changed to alternates.