@gizmochicken What if 18.04 isn't going in the right direction for UT? I read a fair bit about how x has depreciated, or that there's no longer any development of y. 16.04 was the zenith for convergence and thus for UT, so surely it makes sense to make full use of the features developed there...?
The situation is a bit more nuanced.
16.04 is much more like 15.04 and has many of the packages Ubuntu Touch depends on, the things that work now will mostly work after recompiling. The recent breakage of the Unity8 desktop on 18.04 is just the tip of an iceberg of changes that make 18.04 difficult.
But there are also things that don't work now: Convergence needs better support for applications not developed for Ubuntu Touch. For the future, it is necessarily to adopt a newer version of Mir to get Wayland support and use applications that can use Wayland. Updating Mir is something that can be done on a 16.04 base, getting the applications needs 18.04.
So, for the phone, the right step is to get off 15.04 in the simplest way: 16.04. This provides a stable base on which to consolidate progress, support the phones and prepare the next step.
The Unity8 desktop is some way from being mature, and doesn't feed directly into the phone goals. Apart from some changes to get it working on 18.04 it needs things from Mir that have not yet been delivered (most significantly the support for X11 applications discussed recently). The work here should probably focus on 18.04 with the intention of preparing the way for the phone.