IR is not magic, and niether are IR remotes. The question is merely what does the remote put out when you push it and hold it? If it puts a single sequence (in Pronto Parlence, a one-time sequence) then adding a delay after it is sent does nothing but ensure that no other IR commands will be issued during that period. Keeping your fingers off the pronto and not being in the middle of a macro ensures the same thing.

But what if the projector expects to see a single burst, followed by no IR activity followed by a different burst? then you need to know what the IR burst after the delay looks like.

But what if the projector expects to see a continuous repeated burst of IR for about 5 seconds. That may merely be a repeated sequence much like a volume up or volume down or Fast forward or Fast reverse on many components. The IR window would need to be checked/edited to make it a repeated burst. I suggest you try that.

If you want to tell what the Pronto is doing look at the IR edit window, I will help you if it is a learned IR command. Cut and paste what the IR window says into this thread.

As I said before it depends on what the remote is really doing!