There are so many other things the Figma engineering and product team should be doing, I’m going to say that if you’re having to copy and paste so many files that it’s the repetitive task that is eating your time – you might just need better workflow or file management.
Have you fully explored the Components and Libraries feature?
I will alter what I think you want by selfishly proposing something that WE need – but might also be the thing you need as well.
Instead of duplicating, you could send a “Window” or a “Mirror” of any object into another Section or Design File (or FigJam). So, when changes are made at the Source, they are seen everywhere the Window is on the Canvas – across all the files that have that Window/Mirror. Components don’t do this, because you can’t grab things from components.
Let’s take a UI Kit, or a Brand Kit, or Design Guidelines. Sure, you can make every object in that kit a Component, and you can one by one import them into your other files. (Here actually your idea would be interesting, which is to just magically send a component to some group of files.). However, UI Kits and Brand Kits and Design Guidelines and all that are usually designed and structured themselves… So you have to recreate the design of the parent object, or the meta-components, in order to have all those actual components be organized in a schema and with documentation that makes any sense. Either that, or every time a designer wants to browse the component library, they have to LEAVE the file they are in, and GO to the UI Kit. It makes no sense.
Or let’s say that I’m creating variants on your designs. And your designs are complex, pages and flows and mobile and web and tablet. In order to see your files in my workspace, I have to duplicate them. Well, then they will be out of Sync as soon as you change something. Or, you could make everything you designed a component, and then you will have Page Components that reference Section Components that reference Element Components that reference Composite Components that reference Token Components. And I can’t grab anything from your design without retracing the Nested Component Tree like 26 layers deep. And by that time I forgot what I was doing.
That was a ramble. I’m in full support of a slightly less time consuming way to duplicate or send any object to another File. However, I think that will lead to another fiasco that needs cleaning up. So, I used to opportunity to suggest Mirrors/Windows as well.
Sorry to hog the mic, mic drop.