You're exactly right and thank you for carefully reading! I very explicitly said that there was a multi year round trip for information even in the best case (e.g. Alpha Centauri), to get out ahead of the well-actually's.

As you noted, some of the gains could be signal power, redundancy, the ability to maintain a quality signal over arbitrary distance; but most importantly, seeing the universe from the perspective of the lead probe in the relay, some arbitrary distance away.