Do I need to reinstall Material Packs and/or HDRI Collections through the Plus HUB to use them in the Plus Library?
Yes. If you own the material packs outright, you will need to reinstall them through the HUB to use them in your Plus Library.
While leaving the products you've installed previously will technically work, it can cause slowdowns in C4D if textures are referenced in more than one place.
To install the Plus Library, click here for a complete installation guide.