well it depends. sometimes i use it just to delay a scene switching, or to delay some other non-actor related thing such as delaying music playing or such. i do have actors im killing that have the behaviour that uses 'do after' inside it, but this all worked ok in 2.2 so i noticed it fairly soon after my game worked better in 3.0 (as in, after it worked better so i could actually check things out, what was working, what wasnt.. and this one i noticed fairly quick)