If I'm not mistaken there's a repeatable quest to get gold essence and thus gold seeds.So how do i make casts for tinkers tools in dreamworld ? lot of copper no aluminum ... ( mob farm to get gold ? )so do I need to repeat all the steps from over world ? Maybe a new quest for dreamworld progress ?
The fact that you can't take seeds with you does not mean you can't reproduce them.
Otherwise a mob farm is a viable albeit very slow alternative.