Another update for the brand new 'Redstone' next-gen branch of Windows 10 Mobile, available to all insiders with native W10M devices and who have signed up to the 'Fast' ring. See the details below, but essentially it's fixes and news of visual voicemail, network depending....

From the Microsoft post:

Build 14267.1004 is the same build we released on Friday but with two very important fixes and one new feature:

• We fixed the issue reported by Insiders in Build 14267 where the Lumia 550 no longer charges or connects via USB. If you hit this issue on your Lumia 550 – we have laid out guidance on various methods to get back into a good state here.
• We fixed the issue preventing Visual Voicemail notifications from happening.
• We’re introducing Visual Voicemail for dual-SIM devices such as dual-SIM Lumia 950 XL! Work for this feature was in Friday’s release but due to the above mentioned bug impacting notifications it was not working correctly. But now the experience should be working as expected.
• We’ve released an update to the People app that brings back the history feature. For a given contact you communicate with, you can view the interaction, whether by today, yesterday, last week etc. Right now, your Skype messages won’t show up in history yet but we’re working on enabling this in a future update. Also – we’re tracking a bug in which opening an email item in history might not take you to that specific email.

We also have some additional known issues we’d like to note:

• If you have the Windows Feedback app pinned to Start, after upgrading from Build 10586.107 it will no longer show as pinned.
• We are seeing reports from Windows Insiders of issues connecting to wireless displays. We’re investigating.
• When using Continuum on the Lumia 950 XL – the trackpad experience is not working correctly.

As a reminder, we are initially making new mobile builds from our Development Branch available only to devices that shipped with Windows 10 Mobile. Currently this includes the Lumia 950, 950 XL, 650, 550, and Xiaomi Mi4. Today we are also adding support for the ALCATEL ONETOUCH Fierce XL. We plan to expand to other devices once we start releasing Windows 10 Mobile to other devices. If you are a Windows Insider on a device not mentioned above, you can stay in the Fast ring and sit tight until we expand to other devices or go back to Build 10586 and switch to the Release Preview Ring to continue helping us test Cumulative Updates. For more information about our rings and branches, I highly recommend reading this post here in Insider Hub.

Good stuff, and great to see new, non-Microsoft devices continuing to be included in the Insiders programme overall.

For those keeping score, Windows 10 Mobile build 10586.107 is the latest candidate for making its way out into the production world of non-native W10M devices. I'd bet on it being packaged for an over the air update to the Lumia 640 and 640 XL in the next week. Unless some showstoppers are found, that is. I can think of a few frustrations of my own...