I found out, since I have FPV-OSD now, that the FC40 comes down with 4m/s while in RTH/FS, and there's nothing we can do about it. This is TWICE the maximum safe descend speed for 9450's or 9443's. I switched it out of RTH immediately when I noticed it, realising that 9" props are in fact posing a hazard, every time I fly. I rely heavily on RTH. Use it every flight to come home. I must add that only recently I started to use 9443's (from my P2) because the old 8"s where a bit scuffed and still fly great but vibrate a little too much. Food for thought. Why does DJI allow us, P1 and FC40 users, to fly our birds into pieces and doesn't do anything to warn us, while at the same time, all P2(V3+ whatever) users are restricted to 2m/s and patronised like school kids with their Naza/Phantom mode. Why wouldn't we be able to change the max descend rate in Naza-M to 2m/s? Right! According to DJI, the 9" props are not standard for a FC40 but they are for a P2. Now why don't they advise P2 users to use 8"s? Because that would shave off 2 minutes flying time (although very safe) and that's not cool in this business. Flying time is the magic word. Simple really. I guess I'll order a couple of 8" sets. Don't want to see the bird tumble from the sky just because of props. Besides, new undamaged 8" props are extremely smooth anyhow. What do you think about this matter?