Liquid pumps in mixed liquids pump less than 10kg/s

It's a rather ancient behavior that is unlikely to be intended, but was never directly addressed:

When a liquid pump has its lower 2 tiles in one liquid and upper 2 tiles in a different liquid, it will output less than 10kg/s on average, even if all liquid tiles are high density.

In such a case, the "lower" liquid will have 10kg packets, but the "upper" one will have only packets of 2000g and 4000g (choice of smaller packet size seems to be non-deterministic).

The gas pump is not affected by this behavior in two gas mixtures, but is once again affected if there are more than two gases. This is because gas pump outputs only 500g/s, which is half of the pipe capacity, so it can "compensate" for smaller packets with larger packets of the other gas.