I went with official FF 6.6.0 first, updated both Sky Controller and Anafi. Tested with Geo fence off, since I read about no altitude limits...but saw no slider to 4000m. Uninstalled FF 6.6.0 and side loaded FF 6.5.2-rc4 and slider is now there with geo fence on. I don't allow FF 6.5.2-rc4 to update the Anafi firmware when it prompts.
I also have a similar result with slider to 4000 m on Altitude by installing FF 6.5.2-rc4 together with updating firmwires on Anafi at 1.6.1-rc4 and Skycontroller at
1.6.1.
The purchase apps can be resumed without problem. But it has some tricky when the screen pop up to pay money, just click the lowest bottom icon to confirm rather than the fake ... visa... xxx., then, the apps can be resumed.
I just wonder whether this mod FF 6.5.2-rc4 will have longer range or not similar to FCC mode FF 6.6.0.1.