Actually, I do not consider the Nik plugins as an extension to DPL. This package was acquired by DxO because of the U-Point technology which was integrated into DPL for local adjustments. Now that they own this package, they decided to sell it as a product by itself and I use it as such. The Nik Collection can be used from other programs, especially PS and LR. So it can also be purchased by users who don’t want to acquire a DPL license.
I’m sometimes using the NIK plugins because not all the cameras I’m using are supported by DOP/DPL (e.g. Fuji cameras with an X-Trans sensor). So my statements about what should be done about the Nik Collection are not based on my use of it from DPL. For a significant part of my images, I just cannot use DPL. In that case, the features of the NC plugins are not necessarily duplicating any existing feature in the host application from which I use them. For example, converting to b&w with Silver Efex and U-Points is more effective than the same operation in Lightroom. For images produced by cameras supported by and post-processed in DPL, this might not necessarily be true.
So I’m talking about the product by itself and about what should be done to make it more consistent and easy to use from any environment, including DPL if needed.