Hello,
As Roger's design had no competition from other flag entries, there were Third Nationals already flying in Richmond in January 1865 despite it not being taken up by the CS Congress until the next month nor officially enacted in March. The newspapers and other sources were already reporting his design.
I have documented flags for Chimborozo Hospital and some units of the CS Navy's James River Squadron already using these flags. A few did make it into the field as battle flags including the Upson County Militia of Georgia and the 5th Florida Cavalry Battalion among them.
Greg Biggs