Update.
Turned in the Ergon and picked up a Giant Approach on the shop's recommendation. Sightly wider, more flex. No long rides this week, but I'll give it a test on the trainer. Trainer hours are 10x longer than road hours in terms of suffering in my experience.
Specialized Romin 150mm: No, too narrow. Consider the 158mm version.
Specialized Power 168mm: Maybe. Consider for a longer test.
Fizik Tempo Argo 160mm: No. Sit bone area pain 35 miles into 200k.
(pause in test, rode two 200k brevets on my Selle Anatomica. Which reminded me this is not the right saddle for me)
WTB Koda 145mm test. Very short test as I got sick mid-week. Maybe too short. The Ergon is similar so I'll do that next...
Ergon SM sit-bone pain at 25 miles. Maybe try wider version.
Giant Approach