Figure 453 of book 2 of the M998 -24tm.
Kit, pintle extension.
10 PAOZZ 2540014117519 19207 12342661 PINTLE EXTENSION PART OF KIT P/N 57K1640
UOC: AVY, BVY, HVY, NNN
AVY M1097A1
BVY M1097A2
HVY M1097
NNN M1123
Used only on the M1097 and M1123 series vehicles, which are the heavy trucks for carrying shelters, not the M997 series (Those are A15, B15, H15 UOCs)
As far as the diagrams, it appears to be bolted to the airlift bumper, but does not specify any added reinforcement of the bumper, and the use on code does include the A0 and A1 version of the M1097, so it would lead one to assume that you just need to make sure you have the complete kit that was installed on that series of vehicle. The manual makes no difference between any series of vehicle.
Personally though, you really can't reinforce it enough if you're actually going to be towing with the truck.
Just to verify though, this is the extension we are talking about?
View attachment 797523