Laxus Secret Art is about as relevant as Gajeel's currently.
Erza used her enchanted weapon with a fodder level armor. Also Laxus unlike Erza doesn't play around with his enemies. Erza has shown time and time again to stomp enemies who seem to be on her level when she stops toying around. Skullion saved her from the rest of Erza's assualt. Erza was out of her league.
Kiria only beat Lucy in one hit due to Lucy being low on magical power. Jacob could have killed a full powered Lucy in one hit had it not been for Natsu. He also shown to hit way above Fairy Glitter as he was able to almost destroy Mavis' crystal in one hit as opposed to the multiple hits it took FG to do.
Jacob also forced Natsu to use his second strongest mode for a reason.
Her feats aren't. Jacob gave Natsu trouble and was beating Natsu and Lucy in CQC. Kiria would have been demolished by Natsu if he could use his fire magic lol. Her bladed attacks were guarded by a Natsu who couldn't use it lol.
Why would we bring up her DF when it hasn't been shown and it is not in character for her to use? If we give her DF then Jacob gets his transport lol.