You can expand your Substance Designer library without downloading additional assets if you already have Substance Painter installed. I always configure Substance Designer to access Substance Painter's resource path, which provides extra grunge maps, generators, and materials. These resources serve as an excellent starting point for my materials and speed up my workflow.

Among these assets, the grunge maps are the most useful in my opinion. However, they can be quite heavy, so if performance is important to you, it's advisable to avoid using them.

Recently, I created a leather material that utilized the grunge maps from Substance Painter to achieve interesting roughness variation.