They do do squat... I have used it before with a combat shotgun and I could make it so you could fire very rapidly by lowering them. They do work.
And then I guess the wiki is wrong cause it says shots per 2 seconds. Maybe we should fix that then.
This was obviously made by someone who did not fully test Auto weapons had they tested longer then that initial 2 seconds they would have noticed that the weapon keeps firing every second past the initial first shot skip, if they had tested with an ROF of 1 if not its nearly impossible to even accurately test.
Firing and the ability to Refire is 100% controlled in all non-auto attack animations by sequence tags such that if not present the anims do not even work !!
I will explain there are Sequence Tags -> Hit tells the game when to fire -> Sequence Tag a:X(where X is the anims index) this tag tells the game exactly when your allowed to fire again its not the fire delay its this sequence tag and the only way to make it happen sooner is to alter the anim or set the frequency so that it occurs faster that is it.
For auto weapons the Loop anims just start firing immediatly and the ROF kicks in zero fire delay needed -> for AttackSpins Sequence Tags in the Anims control when your allowed to start firing and the ROF kicks in at that point again zero fire delay.
Fire Delay is a defunct setting not used any longer.