Re: What episode is the most unreferenced?
Hm, not sure how much it counts but both SCE Ishtar Rising (1 and 2) and A Time to Sow mention Seyetik... Just looked it up.
First one just says his hologram was used. Second has Geordi familiar with his terraforming work.
"In fact, I've always found that uh...when people try to convince others of their beliefs, it's because...they're really just trying to convince themselves."
Colonel Kira, "Covenant"