Dirac Live will not see if a "SpeakON" High Level socket is in use or not, and will consequently measure (design + apply corresponding filters to) the subwoofer both in connection to the FL/FR outputs and the LFE output.
So it is recommended to configure Dirac Live without the High Level socket and use the subwoofer output from the device only, and then apply any bass management (i.e. routing bass content from FL/FR and mixing it with LFE to the subwoofer) within the device (i.e. upstream of Dirac Live).
This would ensure an unambiguous filter design for the subwoofer and avoid potential issues with timing misalignment between High Level and LFE.