So I got a change working on the weekend based on the pull request I highlighted and just doing the same thing for _TZE200_iossyxra.
I can get up/down/stop buttons in the ZHA device, so I can pair the motor to the RF Bridge by pressing the up button.
I am happy to share this for anyone who wants it, but before making a pull request I wanted to get the pairing of the manual RF remote control to the dongle. This means the dongle and Home Assistant will see if the manual remote was used, allowing it to correctly track the state of the blind.