This mod provides a few configuration values to change the speed and delay of the Kiln lava. Host only; changes are synced to clients, even if the mod is not installed.
KilnLavaWaitTime - Time to wait in seconds once the campfire is lit. Default is 90 seconds. The vanilla game's default is 180 (3 minutes).
KilnLavaSpeedMultiplier - Speed multiplier of the lava. Default is 2 times the speed. Goes up to 10, but 2x speed is already extremely hard, and I don't think it's possible to outclimb 3x speed.
KilnLavaUpdateRate - Seconds between syncs to other clients. Default is 0.1, or 10 times per second. Going lower than this will make the lava rise smoother, but may cause lag in larger lobbies. 0.1 worked well and didn't cause any noticable lag in a 12 player lobby. The vanilla default is one update every 15 seconds.
Maybe inverse the update rate so instead of "seconds per update", it's "updates per second".