Ranger VTOL - No OSD display in goggles

OK, new Ranger VTOL, Hee Wing’s own FC. Video is HDZero (Race), connected to UART2. In Betaflight this HD needs MSP+DisplayPort

It flies, I have video in goggles, GPS is working (location/height numbers alter in MP), but no OSD at all visible in goggles so far. Nothing I have done helps. Have read and tried to follow the Parameters part of documentation, to no effect.

Hee Wing manual for this FC lists various settings for differing HD video, but HDZero is not in the list. List is Avatar and DJI O3, two methods, then one method for DJI V2

I don’t at this stage need any bells and whistles at all, just want a basic OSD ( Screen 1 default as shown in MP will do) visible from power up. Would be good to turn this off on switch, though at this stage anything visible would be a relief!!

Obviously doing something stupid, but what please, what are the bare minimum settings to get a display?.

Serial 2 set it to display port Its in the drop down menu

Then osd_type 5 msp display port