Disassembled the ROM, the address to patch for 'no-save' is 2CBAh or 2CBDh depending on the ROM you have. And the ROM indeed works now with Carnivore2 when using the provided RCP file. Thanks a lot, gdx!
Sorry, right address for the release 1 is 2CBDh.
2CBAh is for the release 2. The patch to use MSX's PSG causes a crash during the demo on the release 2. (It's probably a protection that has been added)