Don't fork out money for Xpadder - it only emulates a keyboard and mouse! Use Xinput Plus to have your 360 controller emulate a DirectInput one and it'll work perfectly with PSO. As an added bonus you can use it to assign the triggers to buttons, which will let you use them in the game.
This launcher is very useful. Thank you for your hard work.
Do you still plan on adding support for 3840x2160? It'd be great to see PSO running in native 4k, especially with ReShade having full compatibility. Although, extra scaling for text like nametags would be useful as well - at 2560x1440...