Vanilla Minecraft uses unpredictable random number generators for fire spread and lava ignition, meaning two players with the same seed and identical portal setups can get wildly different woodlight times, anywhere from instantly or over 2 minutes, purely based on luck.
Woodlighting Standards replaces this with a seeded system where the time to light a portal is derived from the world seed, an attempt counter, and the quality of the player's setup. Given the same seed, the same portal will light at the same time, every time. Better setups (more burn slots filled, more lava in range) result in faster lights.
@ClearColdWater & VY - w/ testing and feedback
Disclaimer: Changing difficulty mid-timer will change the time to light final time. The same seed on different difficulties will produce different woodlight times and same with different setups.