Microsoft have released a new build of Windows 10 for phones to Windows Insiders on the fast ring. This build is 10052 and is a minor updated to build 10051 released a couple of weeks ago. It is designed to fix issues with the previous build and doesn’t contain any new features.
Fixes in the build include:
Flight mode can now be enabled.
You can now disable data connections.
We fixed the bug in which your phone’s MMS settings were lost after upgrading from Build 9941.
We fixed the issue in which you couldn’t download keyboards for additional languages.
We fixed the issue where the viewfinder in the Camera app gets composed incorrectly on some devices like the Lumia 1020.
I installed the update this morning and it installed fairly quickly (about 20 minutes) and things like flight mode now work but I couldn’t see any other changes. The build number is now reported as 10.0.12534.59.