Your brain is so huge :0
😊
This seems to stop working once you have your Office. I believe the random seed for determining what you find in the valley seems to be set before or as you click "Confirm Plan", which you cannot then use the back button to move past.
Mind you, the tablets are the most numerous collection, the transcripts should only have 6 to find in the valley (Poseidon and Athena are being saved for later builds, 2 gods totally abstained (IIRC devs implied they won't get a transcript because of this), and you get 5 guaranteed transcripts from Argos it seems) and that feels reasonable to not have this easy reroll scumming to get.