Here are the patch notes for 1.2.21, which just went live on Steam.
Tweaked the damage values of fire damage from enemy Scab Bombers and Scab/Tox Flamers
Tick interval changed from 0.2 to 0.35.
Damage scale per tick from [1, 1.25, 1.5, 2.0, 2.25, 2.5, 3.0, 3.25, 3.5} to {1, 1, 1, 1.25, 1.25...