I was wondering the same thing until I looked it up on
Amiga Hardware. Apparently version 7 (and maybe others?) used this rom tower. I also looked up the installation of 3.1 roms for the A3000 and it says just to replace the roms in the tower.
So, unless you just want to buy another rom tower and put the 3.1 roms in it and switch out, it's not REQUIRED.
I have a revision 9/03 and didn't need this.
