It's not so easy for modders to massively blow up treasure tables.
Doing that can become dangerous and result in crashes.
We drifted away a bit from the original theme in this thread
Trouble with dialog system where the later pages were mostly about possible crashes due to item overflow.
In the end a modder who blew up treasure tables would be blamed for upcoming crashes and could do nothing to prevent them other than reverting the massive blow ups.
So while a mod that changes only quality of drops does not change anything in comparison to the original game, one that massively increases amounts of drops like '5 legendary items from every chest' can quickly use up all available item handles. Add some crafting and you have your 'out-of-handles-crash' ;-)
The reported crashes occured when people did lots of trading and crafting and were long into the game. (i.e. when there was enough time to spawn new items)
Adding a lot to treasure pushes the limit further down towards average gameplay. So be careful.
(I'm already thinking of harvesting a mine in a single step instead of five steps so that mine respawn does not add significantly to the problem ;-)