ExpiredReign
Deity
After doing some research of this modifier, (its found in the Aristocracy policy, the 15% to production when that city is building wonders) I have found that it is actually being applied twice to the production, effectively a 30% modifier.
But! Not on all wonders!
Have a look at these screengrabs from a vanilla game.
I have taken the Aristocracy policy and started building some wonders, Great Library, Mausoleum of Halicarnassus & Pyramids.
I haven't made it through ALL wonders, and probably wont, just thought I would post it and share.
I couldn't see anything in the general forum, but then I find the search function on this forum next to useless!
Curiously if you do Google search the top results are from GEM files in the GitHub repo or a discussion on this forum between Thal & Skodkim!
The rest of the pages are all in either Chinese or Korean and look decidedly suspicious to me.
EDIT:
On closer examination I'm not so sure this is happening in CEP modded games!