Chunk sections count randomtickable liquids (just as randomtickable blocks) when being initialized, but during the gameplay, adding/removing non randomtickable liquids (water) from the chunk section modifies the counter anyways.
The only way this currently seems to affect the game is that chunk sections to which water was added after they were loaded are randomticked, even when there are no randomtickable blocks inside.
Comments 2
Yes it is still a problem in 1.16.4. There is no known way to observe the issue ingame, besides slightly increased CPU time. You can reproduce this by loading an empty world and then adding water to chunks. The chunk sections will then be randomticked for no good reason, it might show up in the profiler. The issue I am reporting here is not about the lag, but about the defect that makes the randomtickable fluid counter be essentially useless. When lavalogged blocks are added it will immediately become observable by loading a chunk with lots of water and then removing the water. The lava from the lavalogged blocks would then no longer spread fire.
Please check if that's still an issue for you in the latest 1.16.4 stable release or the latest 1.17 development snapshot.
If this is still an issue, please provide proper reproduction steps or a small video with the debug screen enabled (hit the
F3key) demonstrating the issue.