Yep. Each ability consists of 2 files, Abilityxxxxx.entity and Buffxxxxx.entity. Usually these are named the same (AbilityGaussBlast and BuffGaussBlast for the Kol's gauss shot, for example) but not always. The ability file calls the buff file, and the duration is defined as a finish condition in the buff file as "TimeElapsed".

So, TeleportDisable is a little trickier, but let's see.

In AbilityTeleportDisable:

buffType "BuffTeleportDisableCaster"

So we go to BuffTeleportDisableCaster:

numFinishConditions 1
finishCondition
 finishConditionType "TimeElapsed"
 time
  Level:0 30.000000
  Level:1 0.000000
  Level:2 0.000000

So it lasts for 30 seconds. You'll notice there's also a BuffTeleportDisableTarget, which has:

numFinishConditions 1
finishCondition
 finishConditionType "FirstSpawnerNoLongerHasBuff"
 buffTypeToQuery "BuffTeleportDisableCaster"

Which means it ends when the caster's buff ends. So, you don't need to mess with this one, and just change the TimeElapsed value in BuffTeleportDisableCaster