There exist many fastloading systems for the Commdore 64/VC 1541 combination. Unfortunately, only a few work with the cost-efficient SD2IEC device, a most notable exception is the Dreamload loader system.
However, writing to "disk" is not supported with Dreamload. Due to the customized disk protocol, even using the standard ROM routines for saving require a reset to deinstall the loader system.
Is there a Commodore 64 Fastloader/Fastsaver system that is SD2IEC-compatible? Ideally, it should be an IRQ-loader (i.e. it doesn't affect IRQs during load) and provide a speed improvement for both, loading and saving.