Comment 12 for bug 313514

Add to this hotplug fun, when a new device that uses keys discarted to make place for something else can be inserted at any time.

No remapping is a requirement if you want to support new input hardware by default. To have generic support you need to declare every known extended keycode, so devices the user plug in (which use any subset of those) just work. As hardware manufacturers are real good at finding new extended keys and coming up with new input devices the 255 limit has been passed some time ago. Any form of reduction to 255 codes only results in key collisions with some input device sets.

Current remapping only works for configs customized for a particular device set, where you know the specific keycode set used. Also, every remapping requires a customized set of xkeyboard-config localized layouts. Since the result can not be safely shared, that's a labour-intensive enthusiast-only solution.