Liquiducts/Fluiducts aren't (weren't?) the limiting factor in 1.5, it was the boiler blocks. Each face of a boiler block could only supply enough steam to run one ISE. So you would typically connect 9 Liquiducts to one side of an LP36 boiler, merge those together and run all that steam to your engines via one line of Liquiducts.
My question is, is that still the way boilers work? Do they only put out X amount of steam per boiler block face?
If so, my follow up question is: does an HP boiler require 18 faces be connected to Fluiducts to pull maximum steam, or do the steel boiler blocks put out twice as much steam per face as an Iron boiler block?