Windows on ARM has been on our radar for quite some time. Since these apps rely on the Qt framework, we would need a version of Qt that also works on Windows ARM. This is the case with Qt version 6 but Qt 6 has some fatal problems with broken transparency and buggy rendering in the QtWebEngine on Windows. This is why the Windows version of our apps are stuck on Qt 5.
Yes, Plex for Windows and Plex HTPC can currently be run on ARM devices such as the Surface X. The UI is a bit sluggish but still usable (though even more sluggish when operating on battery).
The playback has most of its load on Direct3D so very little emulated code is used in this process. So the playback is smooth even when running on battery.
