Originally Posted by Toni Wilen

Not sure if this help but I experimented with DKB flasher when I added emulation support. It also returned some similar message (obviously because it can't detect speed under emulation). I think there was command line option to force select speed but don't blame me if possible wrong speed selection bricks the hardware.. In worst case you need desolder the flash chip and flash it manually with correct data. (Or it just adjusts memory timing etc and only makes it slower if wrong speed is selected?)

There is different small FPGA binary for each speed rating that gets flashed at the end of flash ROM which FPGA loads at boot.