Fast Mine
Fast Mine breaks blocks faster and shortens the delay between breaking them.
Settings
Break delay
The delay between breaking one block and starting the next. Vanilla is 250ms.
Break speed
How much faster blocks break. Vanilla is 1x.
Smart
Caps the speed at 1.2x on obsidian and 1.5x on wood.
Randomize
Varies the speed by up to 0.05x each time.
Disable in creative
Doesn't apply in Creative mode.
Decrease break delay
Counts the break delay down even while you aren't mining, so it's already over when you start the next block.