User blog comment:SirAston/URF and the LoL Engine - A To-Do List/@comment-6061249-20140402174642

I have some stuff that would be good here too:

Skarner's shield and bonus movement speed won't stack from multiple casts. This propably goes same for any other self-buff.

Darius. He is able to do something i always wanted to do, but it's almost impossible - double dunk. Simply, cooldown of Guillotine begins to go down right after first cast, even when you're still able to recast and you do it multiple times in succession. Simply, if you keep it at recast long enough, you can do a double dunk against one target. And for U.R.F., you only have to wait for 24/20/16 seconds. Not to mention he'll get a nearly infinite AA reset from Crippling Strike when his target is affected by 5 stacks.

Kog'Maw and x2 Void Ooze. Will the field slow stack?

Maokai's saplings = nuking ambush, or is there a limit of saplings?