The echoes of the distant tide come willowing across the sound....
Speed of light is 299,792,458 m/s
Speed of shockwave in space is 1,500,000 m/s
Speed of light is 200 times faster than a space shockwave.
So if you looking at light from the big bang that is 13 billion years old, you will have to wait 2600 billion years to see the shockwave.
If we see shockwaves from the big bang, then the age of the universe is 2600 billion years old.
If your looking at 13 billion year old light, then 2587 billion years of light already went past you according to the shockwave if it's the first wave.
If your looking at the echo of a shockwave and seeing 13 billion year old light the size of the universe is its 2587 billion light years plus 50% the age of the universe is 3880 billion years.
If we are not seeing the echo, but the actual shockwave at 2587 billion years, and Webb looks at 18 billion years. All we need is a telescope that is 143 times more powerful than Webb. And we will see the real beginning of the big bang.