I'm aware of all those O3 topics that were coming up for a while. I don't wanna blame anyone, I was confused at the beginning as well. It's complicated, there's been that Failsafe bug around and a lot of rumors have been spread. I try to keep you guys in the loop, so here's another post:
ALL statements have been verified between the DJI and the iFlight engineering team!
YES, the new DJI firmware updates fixed issues with the signal stability in combination with the Radio Controller 2. Users reported random Failsafes or simultaneous video blackouts. Fact is, the system shouldn't do this no matter what triggered that condition.
YES, O3 + Goggle + Radio builds a network of communication. The signal stability update therefore fixed a bug with this network as well. It's not supposed to disconnect all together in first place.
YES, the O3 system is dual band. It runs on 2.4G and 5.8G. The stock O3 antenna is a dual band LHCP + RHCP.
YES, a LHCP + RHCP antenna (stock O3) setup on the O3 might give a slight advantage when signal bounces (gets reflected, example multipathing, bando flying or city use).
NO, 2x LHCP won't have a disadvantage in range. In general, single band antennas have better performance than dual band antennas. Are easier to replace and more durable.
YES, video transmission only uses the 5.8G band. Maximum system priority is on 5.8G.
NO, the Radio Controller 2 doesn't "necessarily" need a 2.4G antenna on the O3 air unit. Reason for that is because the whole system is mainly running on 5.8G, the second 2.4G band is for telemetry or fallback when band congestion occurs.
NO, flying with only 5.8G antennas will not cause radio Failsafes. Since the O3 has a dynamic RF mode it will be self healing to always establish a healthy link. So told us DJI...
YES, the DJI Radio Controller 2 is "supposed" to have a better signal than the video transmission. No matter if 2.4G or 5.8G, due to its lower bitrate requirements the video will go dark first. That's the moment of return or punch out with throttle.
YES & NO, a 2.4G capable antenna will not give you a better signal or range. It “might“ but we did not get a clear answer from DJI about this. Technically speaking, 2.4G offers better signal penetration. Example: Complete video loss which only runs on 5.8G. The 2.4G radio link "might" still be used to throttle up blind and regain video. Unclear points: Is the actual output power of 2.4G as high as 5.8G? Will it really make a difference in case of signal loss? How narrow is this greyzone? Why not use ELRS or CRSF for crazy flights where absolute safety is needed (900Mhz)?
NO, the O3 maximum power consumption is not too high for BECs. Just to mention it, we've seen different values with early firmware. DJI provided values as well as iFlight tested values were about 10-13W on a single 9V rail. This excludes the FC consumed power which gets powered from a separate 5V BEC. The Wattage could be higher if O3 and FC are powered from the same BEC circuit. iFlight used BEC circuits are rated for 9V2A (18W) continuous, 3.5A (31W) maximum and limited by heat of the chip which is obviously air-cooled when flying.
YES, there's a lot of different experiences made by various users. We also do not always get clear answers from DJI, neither can we only focus on 3rd party video system testing. We encourage everyone to gather test results and share them. All productive feedback and input is always welcome to help improve user experience.
YES, we're constantly working and testing on that topic. We've been in contact with DJI ever since and have a very close relationship.