Insiders in the Fast Ring can now install Windows 10 Mobile Preview Build 10586.29
Windows Insiders in the Fast Ring can now install Windows 10 Mobile Technical Preview 10586.29, which contains only bug fixes and security updates. The new build is considered a "cumulative update" to the Windows 10 Mobile Insider Preview Build 10586, which has already been available to Windows Insiders on both the Fast and Slow Rings.
The improvements carried by the 10586.29 preview will include an update for the Windows Phone Recovery Tool, which allows those with a frozen or bricked phone to sync it to a PC and re-install a factory image of Windows 7, Windows 8.1, and Windows 10 Mobile. The new build will also add Windows Insider support to some additional devices next week. Those models are the LG Lancet, Microsoft Lumia 550, Microsoft Lumia 950 and the Microsoft Lumia 950 XL.
The minor improvements that came with this "cumulative update" will be part of the final version of Windows 10 Mobile disseminated to Windows Phone 8.1 models. Microsoft has declared that the base build number of this final version is 10586.
Microsoft says that thanks to user feedback, it has improved the updating experience for users, even those with limited free space. Performance and stability for the Edge browser has also been improved. Speaking of Edge, auto-correction has been improved to make it easier to edit the end of a URL, and Bluetooth connectivity is more stable. Lastly, issues that made it impossible for some to send/receive MMS messages have been removed.
source: Windows via WMPoweruser