To give umm, simple breakdown of what is being stated here.

Kaiten is percent increase spent on high potency ability.

Potency increases apply onto the stack before critical damage is calculated. Soooo class that buffs high base potency skills that are used frequently will suffer more greatly when it fails to crit with frequency. At the least that is what he appears to be suggesting.

I do not believe this because there are plenty of classes with high base potency skills that were not adjusted due to "crit variance balancing". It was originally stated to have been removed to reduce action bloat and crit variance. Then why do we have crit materia and critical on armor at all? What game developer implements percentage based multipliers without understanding how deviation over time or outliers work?

Auto crit not only removes the effectiveness of entire substat, it impacts certain buffs such as Chain Stratagem (lowering rDPS of Scholar if Warrior/Sam/Mech is present). If you are Scholar player who happens to focus on optimization you will probably feel that sting however minute the loss is. Ohhh goodie there is a Samurai in the party.. there goes my chain strat!

Besides if this were truly about critical variance they would have simply made Kaiten cause the next weaponskill used to be critical then left it as Kenki spender. No no it is gone now because good players understood which weapon skills to buff with Kaiten while average players did not, the variance between these two groups was too great (especially if the buffed weaponskill was a critical hit). Much much of the easier to spam Shinten > Shinten > Shinten > Shinten instead. No thinking involved in that!