The King James is the one the Jewish people and our scholars believe to be nearest to the truth.
The King James version of Isaiah 7:16 is different to most of the other versions.
ESV: "For before the boy knows how to refuse the evil and choose the good, the land whose two kings you dread will be deserted."
KJV: "For before the child shall know to refuse the evil, and choose the good, the land that thou abhorrest shall be forsaken of both her kings."
The more modern translations emphasize that the land will be forsaken. If you look at the
Hebrew interlinear, the second half of the verse reads literally, "will be forsaken the land that you dread by the two of her kings". This seems to be why the KJV renders it as it does.
But the word translated "by" (mip-pen-ne) actually means "face" and so should be translated something like, "in the presence of", giving the sense that Ahaz is cowering before them. So literally, "the land whose kings you dread" as in the ESV.
This is relevant. The reason why the boy will eat curds and honey is because this will teach him to reject evil and choose good (v15). The context of v.17 onward shows that he will be born and grow up after the judgment on Ephraim and Judah. Isaiah 8:8 shows that Immanuel owns the land of Judah. He is therefore the heir to the throne of the house of David. If this prince grows up in poverty, it means that the time period is after Jerusalem has fallen, since if he grew up in Jerusalem he would be eating royal food. This means he will be born after the Exile.
Note that the KJV does get verse 15 right, where the modern translations don't. The Hebrew clearly says "that he will know how to reject evil etc", not "when he knows etc".
The way to translate Hebrew is to look at the wider context. Here's my latest find:
https://youtu.be/glXyt6A3c0M?si=gjysvqtkOmUpxSOK