In L.I.E.U. (Leveled Items Extensive Unleveler)
This mod aims to increase the randomness that occurs in the game by getting rid of the items locked by level for EVERYTHING. This took me several hours over a few days and have created several new saves with various other mods ensuring there were no hiccups, and I can honestly say that this has worked.
The item spawning has now been completely unlocked so that NOTHING is restricted by level.This includes containers (safes, ammo boxes, duffel bags), vendors (they will have more ammo at the beginning and the far superior weapons available early), and yes, even the NPCs! Level 1 Raiders WILL spawn with Sturdy and Heavy variations of their armor and better weapons, making for a more randomized, challenging, and rewarding experience.
For a truly challenging (read: terrifying) experience, I suggest LL_UnleveledCommonwealth from here. It unlocks the special variant versions of the NPCs (i.e. Raider Survivalist / Veteran, Super Mutant Overlord, etc.) at level 1 and was the inspiration behind this mod.