I installed a PI2JAMMA board with a pi3 into my cab. It's running PinHP and this is specifically setup for the board and set to run 15Khz CRT and Jamma joysticks with no messing about at all. I had spent time looking at the GERT VGA adaptors with retropi , but was lost trying to find what mode to run the CRT at and then I saw you had to add configs per game, but this does not need anything like that and you can tweak it all from inside mame.
https://www.youtube.com/watch?v=cDiYm0tcjt4