phone-type keypad

I use the ‘Programmer Dvorak’ layout in Endeavouros. In Windows, this layout automatically changes the keypad to phone-type (789 on the lower row), and I like it. but in Linux, the keypad file is independent of the layout file. So I edited ‘/usr/share/X11/xkb/symbols/keypad’ manually and mapped it as in phone-type. But after a system update, it automatically changed back to default. How can I change this permanently, and really isn’t there any setting/package for this? Thanks!