Yeah, Qld here. Perhaps it’s only Australians that worry about this because we’ve got all the bugs 
Funnily enough I got it working they way I want today, as follows.
- (Using Bambu Studio, don’t know about Orca)
- Add M960 S5 P0 to the end of Printer start gcode
- Key step. Make sure the light is off before you click Print Plate
- When you click Print Plate, then Send, the light should stay off until the end of bed levelling.
- 2nd Key step. When it starts Layer 1 the light comes on - switch it off again
After that the light should stay off, at least it does for me.
I was also wondering if it has anything to do with spaghetti detection. That would need the light on I think. Mine is on, haven’t tried turning it off.