Technique implies a trick, and from my experience it cannot be a trick.
LRT, Arwen, means you are ready, willing, and able to move on. In fact you are looking forward to it.
It is not the same as going dark, or dim.
And it only works if you are done with the old, ready for a new phase of your life...that might include your wife if she comes back, but likely not.
You said it has been one week...which likely felt like a month to you, but it has only been a week...I am not dismissing your pain, just trying to put this into perspective for you.
And after a week she contacted you.
Why did she talk about business?
I do not know. You do not know, I could hazzard that you are correct, or that it is a safe topic and she felt she needed filler.
This part is up to you. Myself? Once my wife was out and it was clear OM was in her life, I choose not to be. Why sould she get the benefit of me being socially nice to her when I couldn't stand the choices she had made?
It is up to you and what you are capable of.
But LRT?
I do not think you are there yet.
Experience is a brutal teacher, but you learn. My God, do you learn. - C.S. Lewis
Life is usually all about how you handle Plan B. - Jack3Beans
Listen without defending; Speak without offending - FaithinAK