It is not exactly what you wish for but it could help you with collecting all in one Project with the folder structure you wish and migrate than from there, so you don’t have to open 10 project for migrating stuff in one project
1.) Create your collection Project
2.) In this Project Create a folder like 001_Import
3.) Go now the the Project like EffectCave
4.) Create there a Folder with the same name 001_Import (and if needed in the Folder a Folder with the Project name)
5.) Move everything in this folder from the Effectcave
6.) Go now to your Windows files where the Projects are and copy the stuff that is in EffectCave Content 001_Import in the same folder from your Project
For me it is working fine, but the hard part is not the Migration its more the question how to sort the stuff correctly with the other stuff that was migrated without getting to messy
But in theory it should be possible in the same way with what you want.
As Long the UE4 Internal Folder path is intact UE4 don’t bother with the Stuff.
If you manage to use the same path in your Project, then it could work with Copy Past in Windows Folders.
But for this you must first create a Folder Template and Migrate all in it.
I Migrate at the moment all Existing Projects in one single Project this why, because simple copy paste the stuff in one folder is to messy and you have issues with something has the same name.
After Migration I clean up the stuff and move everything to the folder i wish for and delete what i don’t want or need.