I was able to get jzintv installed and running. The only problem I have now is I can't get it to display with a 4:3 ratio. I have used the below configuration file on my Raspberry Pi 3 and it works great. If I launch Emulation Station from the Buster Desktop, then jzintv will display the correct 4:3 ratio in a window. However if I exit out of Buster and run Emulationstation by itself, jzintv will automatically stretch to fill the screen. I've tried making display adjustments in Retroarch, but it doesn't seem to affect it. Other emulators like Stella, Nestopia, and a few others, maintain the 4:3 ratio automatically. Just wondering if anyone else has seen this problem with jzintv or some other emulators?
jzintv = "/opt/retropie/emulators/jzintv/bin/jzintv -p /home/pi/RetroPie/BIOS --gfx-palette=/home/pi/RetroPie/roms/intellivision/composite_colors.gfx -z1430x1070,8 -b10 -q -v1 -s0 --kbdhackfile=/home/pi/RetroPie/roms/intellivision/hackfile.cfg %ROM%"
default = "jzintv"