Hi,
it might be intentional but I've seen those towers are limited to consume 5 units/s per second.
As crude oil has a energy content 1MJ per unit. Therefore it can consume only 5 MW whilst its very basic version is noted to consume 13,33 MW.
So those towers cant consume enough fluid units/s to achieve its full potential.
In addition to that it seems higher qualities only increase the maximum power but doesnt lift the limit of 5s/unit which make higher qualities meaningless.

Suggestion:
Do as the normal burner towers do. They consume items/s based on their energy content. This would also lead into making them a valid solution to other liquids as light oil as they have lower energy content values.
Benefit:
Use of the towers at its full potential.
Higher qualities make sense again

Thx for considering! :-)