So, I have always done the Dragonborn DLC after the main quest, but the one line of Miraaks "I could have just as easily slain Alduin, if that had been my goal..." made me think...

what does Miraak say instead if you have no completed the MQ yet?

you have done little beyond killing a few dragons.

Except that might start capitalized.

What does he say at the start when he firsts meets you when you haven't done the MQ.

If you have he says: "So it is true, you have slain Alduin..."