I accidentally posted my feedback regarding your mod in the wrong forum thread, because there is also a mod named "Copy and Paste Modules" which I confused with yours for a moment. So here's my feedback after using your mod just for a few hours:
Thank you a thousand times for this. I wished for a simple copy and paste feature ever since I got to use blueprints for the first time. The blueprinting system in itself is such an awesome idea, but the interaction with it is so damn weird. The new blueprint library maybe helps managing tons of blueprints, builtin import/export is also nice, but the actual handling of them is just horrible in my opinion. I don't understand why this was implemented as items in the inventory (my guess would be old code that didn't fit new ideas, like it always is in software development :) especially if you're a small team and not a mega corp with hordes of developers)
I simply hate fiddling with blueprints in the inventory, so I only use them to tile down e.g. mining outposts and train stations, or other "bigger" projects. Maybe I'm just using the current blueprint system wrong all along, but I'm using the quickbar for example and I'm unable to use it efficiently.
I've now played a few hours with your mod, and this feels like inserting Productivity, Speed and Efficiency Modules into my brain. I had so many horrible parts in my factory which I always dreaded to refactor, simply because it would be too annoying to do. But now, with your mod, I got so much done in so little time.
Again thank you and well done. The Devs should integrate this into the base game asap in my opinion, because this would instantly improve gameplay for everyone.