4th job Single Target DPS

If someone can verify that, I'll change it.

Chains of Hell has two parts to its attack; the delay you have is the actual attacking portion, and there's also a delay involved with the snatch aspect which is another 660ms. I have no idea if it was changed in Big Bang or is boosterable.

Under the assumption that this is still the case in Big Bang, and that both portions are boosterable, Chains of Hell has 1187.5%/s, and Upper Stab has 1302%/s DPS after accounting for Final Cut's passive. The critical makes the difference in Upper Stab's favor only 5%/s or something like that. I'm not sure if there's some other delay involved in spamming Chains of Hell where you can fit Upper Stabs in between to improve DPS though. Also, your spreadsheet has Dual Blades using Normal (6) Boostered speeds.