When the Absconder vents, they see the text string 'AbsconderTime' saying '{0} seconds until you teleport back to the vent!'.
This updates as seconds pass. Pretty self-explanatory.
Basically, when they vent, they teleport back to that same vent after x (depends on a setting) seconds.
Quite strategic and not too difficult to code.
Settings:
Kill Cooldown (default: 30s).
Time Until Absconder Teleports (default: 5s)
If you say this role is too powerful, then:
(almost) No role in the mod is too powerful or not powerful enough.
It all depends on the host's settings.
Any role with a kill cooldown option is not too powerful.
Time Until Absconder Teleports could be set to 2s or something, as well.