Yes, the multiple item version works as expected.
No, the single item version cannot be used multiple times in a GCT. You can see why this is by looking at the game's memory.
The instruction is replaced:
807B97D0: 4B8490F8 b 0x800028c8
However when I apply the code again:
807B97D0: 4B849118 b 0x800028e8
The first code is still in RAM, but since the branch address is updated to the latter code, so only that one will be executed.
No, the single item version cannot be used multiple times in a GCT. You can see why this is by looking at the game's memory.
The instruction is replaced:
807B97D0: 4B8490F8 b 0x800028c8
However when I apply the code again:
807B97D0: 4B849118 b 0x800028e8
The first code is still in RAM, but since the branch address is updated to the latter code, so only that one will be executed.