You probably shouldn’t bring everything over – or, at least, you shouldn’t worry about every thing you bring over being perfectly neatly organised in the new place. It usually isn’t worth the effort.
We’re just chatting about the ’standard zeros’ in another thread. A recent development.
One of them is AC.09 Archive. So for every category, assign ID .09 to be archive.
Now you’ve got this nice middle ground: your stuff isn’t just lost, outside your system. Nor do you have to worry about exactly where it goes inside your system. Just find the closest category and dump it in the .09 folder.
This .09 folder’s contents will, therefore, be a mess. That’s okay. Ideally you’ll never need this stuff again; it’s there just in case.