Also of hackerly interest, I have modified a CD Graphics decoder to handle CD-EG: https://github.com/hcs64/cdgraphics/tree/cd-eg , example: https://extended.graphics/VINY-1/
Did this require an external decoder box or were there players available with the decoder built in?
Victor/JVC sold a few decoder/karaoke components (VS-G2, VS-G3), as in this '92 catalog: https://extended.graphics/images/Mezzo.1992.2-4.pg10.jpg
There was integrated support in a karaoke machine from Victor (KX-G1-H) and a CD player from Sony (CDP-K2EG, '94 catalog: https://extended.graphics/images/CDP-K2EG-94.2-full.jpg). There were varying levels of support on the NEC PC-FX and some CD-i systems (GoldStar in particular). I've also seen the logo on some LaserDisc players but never tested one.
The Sega Saturn is the best and easiest to find, though! As far as I know there hadn't been a commercial CD+EG disc released since 1992, and the Saturn was out in 1994, but I guess it was just a little extra BIOS code by then.