I have the Pre-Release 2 and I tried out the Blast Furnace and Smoker to see how fast they took to cook compared to the regular Furnace. All 3 performed REALLY slow. Slower than it should be, especially the Furnace and Blast Furnace.
This must be a bug, because the Furnace was faster in 1.13.2 and now it's incredibly slow. Even the Blast Furnace and Smoker (which is presented to be A LOT faster than the Furnace) are the same REALLY slow pace to cook their separate items.
Cannot reproduce. Please attach a screenshot while in-game with the F3 screen open.