Help with Sevcon Gen 4 size 10 controller

Hi as per the subject, has anybody got any practical experience on these units, primarily looking for a firmware update, currently connected to a Yasa P400 motor, and cant get any support from Yasa or Sevcon, so out in the cold, but if unable to resolve, would consider a Reinheart controller, or similar, if set up for the Yasa, in exchange for a Yasa motor, as i have several of them, still new in their original boxes. Yours Dave