Okay, So I created a listing using the Unreal Engine format and as an Asset Pack. It is not perfect as it still does not allow version types to download in Unreal but it does load into the engine perfect via the Fab plugin. So that is awesome! There is still an issue though where the asset folder just imports into the main Content folder because it is an Asset Pack.
Initially it was declined because the folder structure because I had the Content>PublisherName>Package like-
Content
-PublisherName
–Asset
So changed it to get the product to publish. Is there any way though I could setup asset packs to go into an additional folder like my Publisher Name or even Fab>PublisherName>Asset like Megascans is being imported from Fab?