Where to add new feratures to OSD for the Chibios boards

I am thinking about trying to add a feature , or two, to the OSD on the Chibios Ardupilot boards. But a few questions:

  1. How much memory is available for more features?
  2. Where would this code go? ?/libraries/AP_OSD?
  3. who typically maintains this part of the code? I don’t want to duplicate work