While answering this, I ran into the following assertion by OP:

from what I can tell, Vader wasn't aware that Luke was in the Millennium Falcon when the Death Star captured it after blowing up Alderaan

I'm somewhat unclear on whether that's correct or not, so the question is:

1. Was Vader aware that Luke was on the Millennium Falcon with Han and Obi-Wan during Leia's rescue?

2. If he was, what was the point at which he became aware, and how? E.g., during the rescue/escape? At Yavin? At some later day?

While answering this, I ran into the following assertion by OP:

from what I can tell, Vader wasn't aware that Luke was in the Millennium Falcon when the Death Star captured it after blowing up Alderaan

I'm somewhat unclear on whether that's correct or not, so the question is:

1. Was Vader aware that Luke was on the Millennium Falcon with Han and Obi-Wan during Leia's rescue?

2. If he was, what was the point at which he became aware, and how? E.g., during the rescue/escape? At Yavin? At some later day?

While answering this, I ran into the following assertion by OP:

from what I can tell, Vader wasn't aware that Luke was in the Millenium Falcon when the Death Star captured it after blowing up Alderaan

I'm somewhat unclear on whether that's correct or not, so the question is:

1. Was Vader aware that Luke was on Millenium Falcon with Han and Obi-Wan during Leia's rescue?

2. If he was, what was the point at which he became aware, and how? E.g., during rescue/escape? At Yavin? At some later day?

While answering this, I ran into the following assertion by OP:

from what I can tell, Vader wasn't aware that Luke was in the Millennium Falcon when the Death Star captured it after blowing up Alderaan

I'm somewhat unclear on whether that's correct or not, so the question is:

1. Was Vader aware that Luke was on the Millennium Falcon with Han and Obi-Wan during Leia's rescue?

2. If he was, what was the point at which he became aware, and how? E.g., during the rescue/escape? At Yavin? At some later day?