Confusion about PDM Standard and Professional - AutoCad related

Curious as to why, according to the comparison matrix,  PDM Standard does not support AutoCad, but does support Draftsight.

Both generate .DFX and .DWG files. Is there a specific Draftsight file format PDM Standard is compatible with?

PDM Professional is listed as having an add-in to work with AutoCad.  Is the add-in to allow management of AutoCad files, or is it an integration tool allowing PDM functions within AutoCad?

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