Edit>Keyboard shortcuts, and search for "increase" (and decrease). "]" is connected to increase-value-2, but you can reassign it to increase-value-2-more (same for decrease). Or you keep it that way and use the already defined shift-']' when you want to go faster.
You can also attach this to your mouse wheel (Ctrl-Shift-wheel for me).
You can also attach this to your mouse wheel (Ctrl-Shift-wheel for me).