When DJI did not decide to add INAV and Ardupilot to the list of the supported flight controller for the HD FPV system, some people were, at least, disappointed. Long story short: DJI OSD works only with Betaflight. Period.
Until today, DJI avoids the answer to the question if INAV and Ardupilot will be supported. I know there are some talks and there is a chance for native support for INAV and Ardupilot, but the timeline is not revealed.