Long time lurker here. It appears PersistentData folders only apply for unlocking the second level (and maybe something else). I've played abit with folders (mostly deleting and copying one by one) and it seems the unlockables are actually coming from WindowsNoEditor folder - can't really say which file though. If possible, please, update your post with that folder as well, ty (killed 108 zombies on my playthrough as I didn't find anymore).I also updated my big post on page 42 to include the save file that has 7 items unlocked.
P.S. Thanks for the nice hint for reducing the draw distance, I no longer get level error (1070ti).