A digital knob shouldn't need any dragging nowadays with modern mice. Instead you should be able to just point to it and spin the scrollwheel. It's a rotary

A digital knob shouldn't need any dragging nowadays with modern mice. Instead you should be able to just point to it and spin the scrollwheel. It's a rotary motion that feels somewhat analogous to spinning a physical knob with an easy physical transition from coarse-grained spin to fine-tuning adjustment.