The creator of the LUT or a LUT editor can adjust the intensity, but a LUT captures the state of all color and level changes. They are not inherently adjustable. If other tools do allow you to adjust the intensity, they are modifying the LUT in a simplistic manner. You can reduce the intensity of a LUT or any other filter using filters in this order
- Mask: Simple Shape with Width and Height = 100%
- Opacity (here is where you adjust intensity including keframes)
- LUT (or other filters)
- Mask: Apply