Every time one file is opened (4gb) it is unusable and incredibly slow and there isn’t 4gb worth of geometry in the file and can not make any modifications without the file using up all system storage in MacBook Pro
A 4GB 3dm file is completely impractical as you have figured out.
It’s going to be a slog to get it open and clean it out.
Perhaps start with selecting the objects you want in the file, and Export them into a new file.
I have tried doing this but it still ends up being quite large, and I can now no longer open the file at all as it completely takes up all storage in the computer
The only thing I can suggest is to put the file in a Cloud based share location and send a message to firstname.lastname@example.org with the download credentials and description of the problem.
Maybe we can open it with a computer with more system resources.