The third Bester book touches on it lightly, but doesn't really go into details.
It also touches lightly on Crusade as well, giving a quick mention to the Excalibur's "success" in finding a cure to the Drakh Plague; however, the book doesn't, iirc, mention how it was found or what happened to the crew.
There are some small details about events in the telepath war in the book:
We learn that Bester's girlfriend Carolyn from "Ship of Tears" was killed in a terrorist explosion likely financed by Garibaldi. We learn that Lyta died in the Telepath War and Garibaldi is sure Bester is responsible. And of course we learn that Garibaldi had his blocks removed. I also recall a description of Bester walking into a trap that Lyta set up and he sensed it and escaped but many others in the Psi Corps died.
What's mentioned in the book related to Crusade is
The cure was found, but Earth made a new quarantine policy that wouldn't allow any ships to enter for fear of new plagues coming in. Bester had to sneak in through the new quarantine to get back to Earth.