@invzim Could I please ask for an update to the documentation, stating what the A and B button are for? I might have missed it, but I don't see it stated anywhere.
I think this would be helpful. Maybe just an overhead picture with each switch circled and labelled 1. 2. 3. etc and a small text list underneath. I grabbed a picture from online and added some numbers. Feel free to provide info on the functions of each thing and i'll update the list. I haven't even tuned mine on yet, still waiting for ram so i took this info from posts here and irkens site. Let me know if you can fill in the blanks.
This will help cut down on what does

Y/Z button do i think! Hopefully educate some more people on what each thing actually does.
1. RCA AUDIO OUTPUTS: Stereo left and right audio outputs. Red = right channel / White = left channel (these only work when 3 is switched to RCA)
2. VOLUME ADJUSTOR: Controls the output volume for sound via the JAMMA EDGE CONNECTOR ONLY, NOT line level audio via RCA.
3. RCA / JAM AUDIO SWITCH: RCA = Stereo audio output via the RCA connectors line level. JAM = Amplified audio via the jamma edge, downsampled from stereo.
4, LITTLE RED BUTTON: Unused, only used for initial programming of unit. Just leave it be.
5. JAM / CHAM SWITCH:
--JAM = (JAMMA) 5 buttons via the edge connector, button 6 will be via the cps2 harness. You can also get buttons 4/5 from CPS3 harness.
--CHAM = (CHAMMA) All 6 buttons can be obtained via the jamma edge connector. If you set this mode but don't have chamma wiring, button 6 will always be stuck on.
6. CPS2 HARNESS: Connect your cPS2 wiring harness here to wire up button 4/5/6 ( or just 6 if your cab is wired for buttons 4/5 to the jamma edge)
7. MICRO SD CARD SLOT: Used for saving settings, firmware updates, , storing debug logs when needed.
8+9. A / B BUTTONS: These are used to navigate the settings on the OLED screen
10. ENA / DIS USER LOCK SWITCH: This enables lock mode which prohibits and changes being saved? ENA = Enables lock mode and stops any changes being saved (it will show on oled disaply when this is enabled) DIS = Disables lock mode and allows changes to be saved.
Hope someone finds this useful!