It's not simply plugin in a few maps into to a corona material, see attached image. And some bitmaps need gamma=1 others 2.2 etc.. Sure it's not rocket science when you know the trick and use a template in a material lib but having a dozen of these materials in a scene makes it hard to manage. Part of that is to blame on the SME itself because it can't make nested networks so there is no way of hiding parts out of view...
Your original comment was that using outputs from Substance was 'way to convoluted', when in fact it might take all of 60 seconds to plug in a few maps and change a couple of settings. Which doesn't seem convoluted to me at all, and seemed to me, to be the main point of your post.
However, if you had said something like 'is there any way to make current setup even easier', then that is an angle we can happily discuss.
By the way, your setup is incorrect:
* You can simplify your map outputs by using a 'base colour' map, instead of separated diffuse and reflection maps. Then plug the base colour map into the diffuse slot of the dielectric, and the reflection slot of the metallic (through a falloff map).
* The glossiness maps should not be put through a falloff map, but should plug straight in to the glossiness slot.
* The falloff map plugs into the reflection slot of the metallic surface (as mentioned in the first point).
* The metallic surface should get no diffuse, so unplug the input and make sure the diffuse is pure black.
* Make your metallic surface the base surface and invert your metallic map. Dirt/rust/paint/etc. is always on top of metal, not the other way around.