Of course I want to get into it that is why I joined the conversation.
By focussing on a "proof text" you are hiding from the far more important challenge. I have dealt with the Isaiah text as a JW when speaking to an evangelical pastor. If we go down that route this thread will run to dozens of pages and at the end all we will have is a JWesque proof-texting competition. I know all the relevant texts in context very well - on both sides of the debate - and I will pay you the respect of assuming you do too.
Your work is still ahead of you.
By the way there are three persons in the trinity not two