TL;DRBelt speeds should be 16/s, 32/s and 48/s
What ?I'm suggesting that you should increase belt speeds to make numbers clean.
Why ?With the 0.17 changes belts have 8 items on them on each tick. Since the new belt speeds (15/s, 30/s, 45/s) are not multiplies of 2, this causes inconsistent troughput per second.
For example: When you count full blue belts' items with pulses, you get 44 or 46 for each second.
Increasing the speeds to 16/s, 32/s and 48/s will solve this problem and makes calculations cleaner.
Also smelting time of the plates should reduce to 3 seconds to keep the 48 furnace ratio.