I have recently been exploring Designer's Plugin API and working on a tool to automate some graph optimizations!
So far, the plugin is doing 3 main optimizations, the first of which is detecting, deleting and reconnecting any duplicate generators you have. Nodes like noises or tile samplers for example. It will also recognizes if you have any exposed parameters on the node and make sure not to delete those!
Next up uniform color nodes. The plugin will force the node to 16x16 (the optimal size for the Substance Engine) and set all connected nodes back to relative to parent, unless the given node already had manual edits to its output size
Finally, it will set a blend nodes' Alpha Blending mode to ignore alpha if it detects both inputs as grayscale.
The goal being to simply select an entire graph and let the plugin do its thing.
If you have any other ideas of what could be automated, let me know!