A video explaining how to blend height information in substance designer in the best way plus some other tidbit ideas. Some stuff I forgot to mention is that substance designer does have an overlay node you just have to go search in the library search and put “overlay” or “blend” both have overlay. I use overlay often, you may notice the “overlay” and the “blend” node is only color input and output, so if you are using grayscale info you will need to use a grayscale conversion, another possibility is duplicating the overlay node and making a grayscale node inside the node tree and call it grayscale overlay or something like that. Also as mentioned by a fellow polycounterthe gradient does have a grayscale function property inside the attributes of the node. At the time I was tired and completely forgot thanks for pointing it out. 🙂
Various samples using these techniques and graph below. Some are.toolbag2 renders.