What's the purpose of the "converter bracket" (a term used by the Toyota service manual) on the catalytic converter of a 1990 Corolla with the 4AFE engine?

It obviously joins the exhaust flange of the converter to the flange of the front exhaust pipe, but you could do that with two nuts and two bolts. The converter bracket has a 3rd hole in it as if something could be bolted on to it, but nothing is. It would make more sense to me if the bracket were mounted with the rim of it facing up toward the body of the car instead of down toward the ground. At least the rim would serve as a kind of back-up heat shield that way.

Some photos that show the OEM catalytic converter and the converter bracket:

https://i716.photobucket.com/albums/ww164/tashirosgt/OEMCatampBracket2_zps924a6d8f.jpg

https://i716.photobucket.com/albums/ww164/tashirosgt/OEMCatampBracket_zpsb568b8a6.jpg

https://i716.photobucket.com/albums/ww164/tashirosgt/Bracket1_zps58666b54.jpg

https://i716.photobucket.com/albums/ww164/tashirosgt/Bracket2_zps45965b43.jpg