FlashGordon by PulkoMandy is a Flash/ROM board and mostly a clone of Bryce's MegaFlash design, with a different flash chip and integrated mods for a reset button and "disable all ROMs" switch. It can be slotted on a Mother-X4, or plugged to the CPC with the appropriate cable (centronics or HE902 to HE10 female, 50 pins). It can store up to 32 ROMs, including optional replacement for ROM7 (need hardware mod on CPC6128/664 to disable the internal one, no changes needed on Plus and 464) and ROM0 (for use of the Hacker or straight-to-CPM boot or other foreground ROMs). Software is available to manage it (either ROMAN from PNG or TFM's RomManager) and will come pre-installed on the boards.
So there is a new batch of FlashGordon available if you are interested.