Well I tried disabling the Xarcade2jstick service then making all the suggested changes – ugh. I could no longer navigate the EmulationStation UI without determining which random buttons or joystick movement did what … despite double-checking the .cfg file twice and rebooting twice, it just didn’t work. The hell of it was I couldn’t even get further than the Centipede attract screen – nothing I was trying, on either the Tankstick or the keyboard, would start the game.

I finally had to give up and reinstalled the Xarcade2jtick service – I’ll just stick to AdvMAME for my trackball games.