I have a wired motion sensor and powered it externally (using my existing board) and it was recognized by the retrofit kit. However, configuration options for the mode are limited to either a primary, secondary door or window, not specifically as a motion sensor, which seems to be causing me some issues. It also results in constant event updates to status in the apps, as there is no way to disbale a window or door in “disarmed” mode.
It would be great if there was an option to add a zone on the retrofit kit as a motion sensors (assuming you have externally powered it) and handle it accordingly. Maybe a software update?