If you do searches on the internet for RGB modding an Amiga CD32, it refers to tapping off TP9 pins, and of the 10 pins there, if we take pin 1 as the one closest to the center of the board and pin 10 as the closest to the edge, then pin 6 is Rgb, pin 7 is rGb, pin 8 is rgB, pin 9 is C-Sync. Ok, that's fine, but it also states the RGB lines are not amplified, and weakened by the S-video connection; so a good idea to use a 47 ohm resistor on each of the RGB lines, and ground pin 174 on the expansion pack traces.
Ok, however, there is a Sony CTA1145M chip on the CD32 board, which is designed to input RGB and output composite and S-video. I know from the Sega SMS and the NEC Turbografx that you can tap RGB straight off this chip.
Surely, tapping off pins 11, 21, 22, 23 is the better option here?