The touch functionality is basically just the ability to touch the UI.Input element to place the cursor position! The current keyboard layout contains arrow keys to get around this, but the "mobile" layout there does not.

You can call these functions with custom layouts from the top level already in v0.4 preview builds! So if you want to use this layout, or use the layout as a base for your own keyboard, try it withplatform_keyboard_set_layout, orPlatform.KeyboardSetLayout. See here for how that works:
https://github.com/StereoKit/StereoKit/blob/develop/Examples/StereoKitTest/Demos/DemoTextInput.cs#L65-L70