Hello guys,
Thank you for asking.
If you can take a look at our history of Turris OS versions, which you can find in our documentation, which one of you pointed out. Right now, there are two released versions, which are still supported and in near future, this won’t change as we are working on automatic migration from Turris OS 3.x version to Turris OS 5.x.
We are not able to release any new version of Turris OS 4.x.x, which was based on top of OpenWrt 18.06. There were related changes to procd and some important services does not start and this is not something we can release out. End of Life for OpenWrt 18.06 is planned on May 2020 and since Turris OS 4.0, we have a new workflow, which allows us to provide releases more often than ever to protect Turris routers against vulnerability faster without increased maintenance efforts as we can work simultaneously on more versions at once. I can mention, for example, that we are working with upstream very closely and there were merged more than 300 pull requests, which we sent.
Code base for between Turris OS 3.x and Turris OS 4.x (and newer) changed a lot and new features most likely won’t be introduced in Turris OS 3.x release, but it does not mean that there is not going to be any release of Turris OS 3.x. As you correctly pointed out, there is prepared a new Turris OS version 3.11.16, which is in RC. Changelog for Turris OS 3.x can be found here.
If you want to take a jump on Turris OS 4.x version, which takes you almost immediately to Turris OS 5.x version once it is released and in that time support for the Turris OS 4.x should be terminated, it requires to configure your router from scratch by using a medkit.
There is going to be automatic migration, which should cover basic stuff from Turris OS 3.x to Turris OS 5.x, but my assumpton is that for experienced users, there is going to be documentation soon after releasing Turris OS 5.x and so they can provide us feedback.
If you have any questions, please don’t hesitate to us. Me and my colleagues would be happy to answer them.