Not free and not expensive but is doing a great job on relinking bitmaps, corona proxies, xrefs is Library Track / Relink by Pixamoon.
One of the great features it has is that you do not have to open the Max file.
https://www.pixamoon.com/shop/4587562584/library-track-relink-.../9337230
I can confirm it too, we use this tool all the time in our offcie, and it is working flawlessly. Not only that you don´t need to open the MAX files you need to relink, but you can also "batch relink" many of them at once, for example, a collection of trees from your library, or somthing like that. It has many options, one of them is similar to the "Relink Bitmaps" script, automatically search for maps inside a given location, but it also has the option to "set path strip", so you can change just the part of the local/network adress you need, for example changing the unit letter, or the IP adress, etc.
And I agree again, imho, it is not expensive for the use we give to it.