I'm not sure if I'm missing something but when using the standard config with the values set to 1 smelting still happens around 2.5x faster than on Vanilla settings. Is this right? Surely 1x in the config should be standard rate.

Edit: Just for clarity, without this plugin 30 Metal ore in a large furnace with 13 stacks it takes 30 seconds and burns 15 wood. With the default config file it burns just 6 wood and takes around 8-9 seconds. Tested without any other plugins enabled and also restarted the server, times are still the same.