This works for all functions on the original remote. The codes from the built in database are used whenever possible and macros are used elsewhere to get around the toggle bit situation.
This file contains a completed device configuration along with a dummy code that is linked in each keys macro to get around the toggle-bit problem. When importing this device, be sure to place the device "XM" in the upper left box on "Main Page 1" and "XM(X)" in the upper left box on "Main Page 2". This will ensure the devices will link to each other properly. At the "Device Assign" screen click "OK".
Here's an M5 file with the XM Roady's "power" IR command and the 10 presets. Unfortunately, the Roady remote uses a parity bit, so that's all the commands that can be effectively used with the MX-500. Maybe others in the same boat will find the file useful.