The reality is that PAs use a variety of totally different shaders in DS (even if you call it iray) that have different setups, node names etc etc etc. There is only so much that auto can do. All these unique setups have to be treated differently, and even then personal tastes and lighting setups are going to be key.
All I use the "auto" conversion for is to get over the diffuse, bump and transparency maps. I do wish that transparency maps came over more reliably. But I've found that sometimes daz doesn't even have these visible in the daz surfaces tab somehow, but the native renderer knows what the maps are. When daz has tricks like this going on, there isn't much I really expect a third party to do. (i tend to use 3delight hair presets if they exist since they tend to have the transparencies working right)
I think Iray will always be strong for people that want the instant gratification that Daz sells the majority of its users. But I never want my renders looking like what is in the promo images anyway, and I really enjoy lighting and making my own materials. So I'm not exactly the typical user.
While there is some overlap between the iray userbase and the octane one, is not that big really. for a variety of reasons.
Win10 x64 i7 4770K 32GB
1070 8GB + 1060 3GB
DS 4.10 OcDS Latest