I've discovered that the backpacks from Campfire and Wet and Cold do not actually increase the max carry capacity of NPCs in game. This mod fixes that (for vanilla followers at least). The max carry capacity for any vanilla follower will be bumped by 50 when they wear a backpack from the mod "Campfire", or any *large* backpack from "Wet and Cold" (sorry, the smaller knapsacks and such I did not fix). 

This mod DOES carry over fixes from the Unofficial SE Patch, but if you have other mods that make edits to any vanilla followers, they would need to be patched.

I've added the carry weight buff to the perk called Light Foot, and added that perk to all vanilla followers (and then require wearing the backpack, and not being the player character, in order to get the new carry weight buff effect). This brings the side effect of all vanilla followers ALSO no longer setting off traps, so if you enjoy your followers setting off traps like blind idiots constantly you may not want to use this mod. 

I made 3 main files, so that anyone who uses one OR both mods (Campfire/Wet and Cold) can be accommodated... (Choose only ONE main file)

Version A - REQUIREMENTS - 
1) USSEP
2) Campfire
3) Wet and Cold

Version B - REQUIREMENTS - 
1) USSEP
2) Campfire

Version C - REQUIREMENTS - 
1) USSEP
2) Wet and Cold

Enjoy,
~dan (tcbflash)

EDIT - Just a heads up, I've added ESL flagged versions of all the files. I do NOT know when a mod is safe to flag as esl vs not, but i know people will always keep asking for esl these days, so it's there if you want to try it. 
~dan