Ok make up a story about how Vader knows where the Tantive is going…
A transmission is potentially trackable and traceable.
Hyperspace jumps need to be plotted and calculated and every possible course would have to be considered.
“They could be on the other side of the galaxy by now.”
Nobody ever get’s caught jumping away. You might get caught coming out of hyperspace near a deathstar that’s about as far as it’s ever gone. This would totally mess up the end of Empire Strikes Back.
I want to add I really like the movie but I want to see a version that was untainted by re-shoots or any re-editing.