I am wondering how you can set up a orchestral library, especially strings in kontakt, to have a very fast attack so they play instantly?
Even if I go to the settings like in audiobro strings and set the attack the fastest, it's still has a pretty decent amount of attack. Even the staccato ones.

I usually just export the strings as wav and then chop them up to be on time but is there a better solution?

 

I'd say what you are doing is probably the easiest way to do so. Some libraries have a Sample Start slider or knob, which allow you to move the sample start. The delay is provided because there are some noises before the note actually starts to come through, and having them increases the realism. If your library doesn't have it, or the amount by which it advances the sample start is not enough, you're better off doing it manually like how you're already doing, or otherwise it would require editing the scripts, which is not at all a simple task.

Also, while I don't know what genre you're working in, do remember that for string instruments there is a delay between when the player starts bowing and when the actual note is heard. Strings aligned perfectly to the grid do not sound great and reduce the realism IMHO.