Thanks for that. I just updated it successfully on my Ubuntu machine. I had previously overwritten the installed version of dfu-util with a patched version.
I will try out QSPI.
There is a bug in MyStorm::FPGAConfigure(Stream &str) in MyStorm.cpp that I forgot to tell you about before. It stopped it working for me. At line 107 you have "lastread - millis()" which should be "millis() - lastread". Also, I think lastread should be declared as unsigned long not int, or it may overflow. There is a second declaration of it at line 129. The changes worked for me.