BLM Ultima HM Second Lasers Rotation?

I usually use DF and am 1-23 on Ultima HM and am disappointed I can't efficiently farm it and want to improve. On the second set of lasers, my DPS seems to come to a halt because the movement is so intense. I have tried keeping up a fire 1 spam rotation but I have to move and interrupt my casts half the time so I think it is low DPS. I have also tried spamming scathe then fast cast blizzard 3 if I'm low on mana and this obviously has low DPS but I think it's better than spamming fire 1. How do you other black mages handle the second set of lasers in Ultima HM?

I'm no blm, but killing Magitecks near each other severely lowers the randomness of lasers. I found you'll get targeted less by standing on the Magitecks you just killed, but that's speculation.

Thank you for your input. I'm pretty sure once the magitecks get destroyed and the pulse they were emitting stops, then you take less damage by going to the area the destroyed magiteck was at. I'm thinking it might help to have the party clear like the southwest of the room and then take out magitecks in a clockwise direction.