Would like to replace the stock LCD with something, either those with compatible connection or with Lynx AV mod and any cheap AV monitor. There are schematic on AA site but the pinout don't make sense to me. Most LCD has 3 sets of color input (3 bits, 4 bits, etc each RGB channels) plus control, clock, etc

Considering Lynx has palette of 4096 color, which translates to 12 bits it's a reasonable assumption that the data from CPU is 4 bit per color. The schematic shows unused pins on LCD, it may be extra bits for more color (all least significant bits)

All that's left is figure out which pin is which color and bit (assuming it is like other LCD), controls, clock, etc. Then cross reference to other similar LCD that can be adapted or to come up with Lynx to AV/S-Video/analog RGB out for other monitors.