Some of my general thoughts on reproduction carts:
- Creating one requires the destruction of another game as a donor cart. Usually the donor cart is general enough that one copy of that game wouldn't be missed can be used, but with some games your list is pretty limited.
- All money goes to the creator of the cart. While most hackers wouldn't want to profit from their hacks, many are not a fan of reproduction carts being made from them.
Specifically regarding Crimson Echoes, I believe there's a bug that prevents progress at a certain point in real hardware/non-ZSNES emulators, but I'm not sure on the specifics of this.