It seems like most significant agriculture extension programs have advice for irrigating wheat, so presumably someone is doing it, even if it isn't common. If drought is reducing yields significantly I wonder if the amount is going to start growing.

E.g.

https://www.canr.msu.edu/news/considerations_for_raising_irr...

https://extensionpubs.unl.edu/publication/ec731/2009/pdf/vie...

https://ucanr.edu/blog/uc-small-grains-blog/article/irrigati...

https://www.canr.msu.edu/news/considerations_for_raising_irr...

https://waterquality.colostate.edu/documents/factsheets/0055...