Did anyone ever find out what the PLUS versions of the A/C firmware are? For example, I have a new one which has 1.4.10+. I thought that maybe this would be the same as the next version, but when I tried an upgrade to 1.5.30, it started to upgrade, so they must not be the same (I stopped the upgrade at once of course). And in the forum, I also read about some users who did an upgrade and got a +. I asked DJI but they are being very secretive about it. And it's hard to Google or search, as 1.4.10+ just shows up results for 1.4.10.