i think it might be easier to jsut change the default paths for the files and backups, wouldn't it?
I did basically what you are saying to another server recently;
added a nice 3 terabyte drive, and changed all my default paths to use the huge drive.
a "gotcha" to watch for that was a little annoying: the new drive was formatted with 4096 sized sectors, where the original drive was foramtted at 512.
as a result, i could not detach, and reattach, because youy get an error saying this:
Msg 5178, Level 16, State 1, Line 1
Cannot use file % because it was originally formatted with sector size 512 and is now on a volume with sector size 4096. Move the file to a volume with a sector size that is the same as or smaller than the original sector size.
but you can backup and restore with no problem.
here's the path in facets to change the defaults:
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