I have an Omega Flash Junior and my SGB doesn't detect it. Just shows a black screen. It has battery and SRAM support so I'm unsure of the issue here.
Ok, so I've read a bit about this Flash cart (the EZ Flash Jr) and apparently it have some issues with the Super Game Boy, that is not part of the "supported devices" on their websites.
I've read on reddit that you have to "press the reset button on the cartridge twice" to make the SGB detect it. Could you please try this too hoping it will fix the problem?