I've followed the developments around Kirigami for a while, mostly with a focus on its usefulness for convergent applications. While I know that the convergence aspect of Kirigami was included but not a high priority during the initial releases of Kirigami, I feel now might be a good time to mention some of the concerns I have regarding Kirigami and convergence.

So far, Kirigami does allow for nice UIs that scale well between smartphones and tablets, but this seems no different than what's already being done in Android and Windows 10. I see the same problem when Kirigami-based application end up on the desktop. They are basically no different than the tablet version of the UI, which makes them feel uncomfortable to use.

I'd like to explain why (I think) a tablet UI feels so uncomfortable on a desktop (or laptop)

• For a tablet, screen space is at a premium. This is because of a combination of the smaller physical screen size and the course-grained input method (touch-based). So we need things like big buttons for our fingers to touch, but the screen is small so we need to optimize for space as well. So you end up with hidden or minimal menu's, like drawers or the three-line menu button. This works well when you only need to consume content, but it makes it harder to create or edit content since this functionality is usually hidden away. For this reason, I'll call this a consumption-optimized UX.
• For a desktop, screen space is not at a premium. Even with the same physical screen size as a tablet, the more fine-grained input method (keyboard+mouse) allows the user to make much better use of the available space. Of course, desktops usually have screens larger than tablets. So with plenty of screen space available, you can optimize your UI towards making functionality easily accessible. This makes it easier to create and edit content and pretty much matches what we know as the traditional desktop UIs. For contrast with the previous and its capability to edit and produce content easily, I'll call this a production-optimized UX.

This mismatch between using a consumption-optimized UX on a device that's more suited for a production-optimized UX is why (I think) these tablet UIs feel so uncomfortable on a desktop (or laptop). A good example to illustrate such a mismatch is having to "swipe" with your mouse in order to scroll through a list.

I think that, in order for Kirigami to support a useful form of convergence, we need to think about how to convert between UIs for all device classes, not just between smartphones and tablets. This needs to take all aspects of the device class into account, so I've created a vision for each available device class that should provide guidelines on how the UI should be designed for that device class. I also try to link each part of their UI to their device-specific counterpart (as currently implemented), which should illustrate how you might convert between device classes. I also created a forum topic for feedback, which mostly contains information about decisions I made while creating the wiki page.

Now that Kirigami seems to work well for smartphones and tablets, I hope I was able to provide useful feedback on how we might improve this even further.