Retro Erick is presenting in video the a new CGA card wi tested with the MCE2HDMI. This card is able to do CGA composite and can be bought on Aliexpress. The MCE2HDMI can be bought on Serdashop (where I bought several things, including a few weeks ago two waveblasters card to get MIDI on my PPC 640 without connecting my Roland expander). You can see another Retro Erik video presenting the test of the MCE2HDMI.

You must know that the MCE2HDMI is none other than the RGBtoHDMI by Hoglet67 which exists for many others computers (8 and 16bit), not only for PC with Hercules/MDA/CGA/EGA, but also the Amstrad CPC and CPC+. A list of vendors of the many RGBtoHDMI is available.