I just released a version that SHOULD support SD2IEC devices. However, as I don't have the hardware to test it, I’d be super happy if you could try it and give me feedback whether it works or not.
So, I tested loading from the SD2IEC. it works perfectly, with or without a fast load cartridge. Of course, I wait 5 to 10 seconds for the next part to be loaded with a fast load cartridge instead 1 minute and half.
Here is a photo of your game loaded on my real C64 using SD2IEC.
Thank you for testing and especially for the photo - I love it! I have no idea how the fast load cartridge can work, but I am happy that it does. I implemented a simple failover mechanism. If the installation of embedded fast loader fails, then I just use kernel's LOAD and SAVE.