The question is what does the Confederate Battle Flag mean today ... not yesterday ...
The OP is correct about the origins ... the "Stars and Bars" was too much alike to the "Stars and Stripes" ... a bad thing on the battle field ...
After the Civil War ... veterans on both sides were recognized ... and one benefit of being a veteran is have your coffin draped with a flag ... and even the Yankees thought it cheesy to use the "Stars and Stripes" for Confederate soldiers, and using the "Stars and Bars" was completely out ... so the Battle Flag was used ... nice, simple, easy ... as I understand the matter, this is when Mississippi included it in her own State Flag ... roughly 1900 (?) ...
Then the KKK adopted it for their own use and it became the symbol of Jim Crow ... and the Southern Lifestyle that Jim Crow created ... pecan pie, negro housemaids, NASCAR and Friday Night lynchin's ... Good Ole Boys jes' havin' fun is awl ... and this is when Georgia included the Battle Flag in her State Flag, 1960ish, right after Brown vs. Board of Education ...
Today it represents poverty, stupidity and the pride of being both ... some fanciful romanticized idea that the Deep South isn't a total shithole, and always has been ... and folks too ignorant to know the difference ... if you love Dylann Roof, then fly that Battle Flag ...