I'm slightly baffled... why wouldn't it?
Afaik one can define loot tables and also add specific items to NPCs/objects. Wouldn't it be possible to create a table with nothing or just unimportant stuff like gold and some mats in it and add the important stuff like handcrafted uniques if necessary with scripts?
Heck of a work ofc.
If you remove randomly generated loot, there will be no items in the game. All treasure tables are, by their nature, randomly generated loot tables. Containers, NPCs, traders, corpses, quest rewards, and so on and on all rely on those tables. If you clear those tables, you'll have to hand place loot in every single container entity in the game. Ain't nobody got time for that.