I would like to take a question, of the Ancient Wonders of this chapter Temple of the Spirits, this wonder at level 1 provides 905 unurium per chest of the tower, 48x905: 43.444 unurium per tower completed??
Short answer is yes, but you also get unurium from the mystery chests.
You must have 603K required culture for it to give 905 per chest. The required culture in my live city is 750K, so I get 1125. The second benefit gives half the amount the first one gives for
every piece of event currency you pick up. That will produce a lot of unurium during an event.
While waiting for chapter 19, the AW doesn't have much, if any, value. If things go as they have in the past, the chapters after a new good is introduced is when you begin to need quantities of it. There will be 2 ascended goods to produce and I bet a good bit more A1 will be needed than was needed in chapter 18. Plus more unurium to complete techs. Assuming that is the case I have built the wonder to level 11 and will let is sit there. Actually, I probably should have waited longer before upgrading it since it only need to be level 1 to confirm how it works.
As with most wonders, its need will depend on your play style. I never built the Sunset Towers, so have a 10% seed decay rate, which means I'll need to produce more of them in the trader instead of mainly producing unurium.