New keys are being added to the object model with each release as it is developed. You may wish to update to 3.4 betas to see what else new has been added. You can get a read back of the object model from the plugin or by sending M409
https://duet3d.dozuki.com/Wiki/M409
https://duet3d.dozuki.com/Wiki/Object_Model_of_RepRapFirmware