I have similar problem. I found the only way to set defaults for a new input device (which also applies to Xorg re-adding the same devices at some arbitrary times like suspend) at runtime, without restarting Xorg to pick up modified xorg.conf, is to set xkb* udev properties on a device (for example by adding new rule and reloading udev).
More details: https://github.com/QubesOS/qubes- issues/issues/3352#issuecomment-400292279 ** Bug watch added: github.com/QubesOS/qubes-issues/issues #3352 https://github.com/QubesOS/qubes-issues/issues/3352 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-settings-daemon in Ubuntu. https://bugs.launchpad.net/bugs/1246272 Title: Keyboard layout changing randomly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/1246272/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
