I would say the default mod settings for crafting speed are too small for how massive they are. I set them from 2 to 10 myself for furnace and assembler. Now even without speed modules it outputs 1 red belt worth of plates. It's not much but that's where modules and beacons will come in at lategame. But we do start using trains earlier than that, and it's very disappointing if it doesn't even replace a regular 48 steel furnace array, it was less than 1/4th that rate.

Many of these machines are easy to find at the start of the game, and you can build your base around them. Significantly increasing their speed could upset the balance in the early stages of the game. But if that’s what you prefer, feel free to adjust the settings as you see fit. After all, that’s what they’re there for. I find the default settings to be quite balanced.