Implement cache of user's previous page so when we post/save anything, it immediately goes back to last page and processes/posts in background (no 5 sec. load delay)?

This 5 second delay between saving changes and posting transactions is ridiculous. I am sure there are a million things under the hood to keep the platform functioning, but this save/load delay has to be put at the TOP OF THE LIST of things to fix. Please and thanks. Why not?