Poison/Wither Damage Changes

Every level of Poison/Wither currently reduces the time between damages by half (i.e. you take poison damage twice as fast with Poison II than Poison I). However due to damage immunity (which prevents you from taking damage faster than 0.5 seconds), Poison 3+ and Wither 4+ have no additional effect over Poison 2/Wither 3.

To allow higher levels to have an effect but keep the same DPS, every additional level of Poison and Wither should add a half heart to (or double) the previous level's damage (e.g. Poison 2 would do a full heart of damage every 25 ticks instead of a half heart every 12 ticks, Poison 3 does 1.5 hearts every 25 ticks). Poison would still be unable to reduce your HP below a half heart.