Hi, I test fluid intake at the range of 5, expecting to clear a regular cube, and here are the final results:


Every time the result is different, so here are two possible results.

Version 1.1.1
Forge 14.23.1.2583

That's because in addition to the cube range limit, the device also only has a limited amount of path nodes to find the fluid blocks. By default this is 3 x range so in a clean area with no obstacles every block should be reachable. Here eventually the pipes and the tank may have been an obstacle.

However there is a config-option called fluid_io_path that allows you to change the path length.
If you increase it to a value of 4 or 5 the cube should be drained cleanly. When operating with such small areas you can probably even set it to much much higher values without noticeable performance impacts.