It's actually because I have other melee jobs that Viper hotbars are so annoying to me. In order for Viper to make sense to me, slots that I universally use for things like True North on other jobs simply can't be used for that purpose because they need to efficiently line up with Twinfang/Twinblood.

I'll give an example, I place Sprint on a face button because generally, if you need to sprint then you *immediately* need to Sprint. Every single other melee can get away with 3 aoe "spam" buttons to make room for Sprint, but since Viper has equivalent aoe and ST attacks, I instead have to have a dedicated aoe hotbar to swap to with R1 where it replaces all of the ST attacks and on the original bar, I have Uncoiled Fury instead.