Delete & merge folders & assets in Unreal without breaking everything

Often I end up with duplicated assets and I want to combine the folders in Unreal.

Heres how I learned to do this without breaking everything.
First select the extra assets and drag to the folder you want to merge with, choosing MOVE instead of Copy from the context menu.
Sometimes it will say an error say “the following assets could not be renamed”
In this case select a single asset and Rclick/delete.

You then get a dialogue box like the one shown here…

Basically you need to tell unreal to use the original asset and not the unwanted copy. In the pic above I need to replace the reference to UV_Checker_Mat. This is done by choosing the original UV_Checker_Mat asset from the dropdown None above the red Replace References button.
Then hit Replace References, it will ask if you are sure then hit OK. Then Save Selected from the next dialogue (seen below)

Repeat for each asset in the folder – laborious yes!
(In my case its the Content/Bonz/Materials folder im trying to get rid of in the top image.)

Most important step!
Finally when your folder is empty, R/click and choose Fix Up Redirectors in Folder. These are little files that point to where the assets are. Doing a Force delete will sometimes get rid of these pointers and that’s what messes up the assets. Fixing redirectors ‘cleans’ them up and this step means we can now safely delete the empty folder.