rare venture
A split enhancement would just put a line through the center of the card horizontally.
A split card allows 2 Seals to be added to the card Example (Red Seal + Red Seal or Gold Seal + Red Seal) so on and so forth.
A split card would also allow 2 separate foil effects or 2 of the same effect like double Polychrome.
I know it would take a while to build a perfect deck with like double poly + double red seal but I think it would make for interesting games and crazy outcomes.
mystic crescent