There are a few options.
Free Option -
Fusion- Generate a 3D LUT image.
- Apply whatever effect you want on the 3D LUT image.
- Analyze the 3D LUT image in Fusion.
- Export 3dl from Fusion.
Cheap Option -
Look ConverterSame as Fusion
- Generate a 3D LUT image from Look Converter.
- Apply whatever effect you want on the 3D LUT image.
- Load the 3D LUT image in Look Converter.
Pro Option -
3D LUT Creator- Apply whatever effect you want on the 256 HALD image that comes with 3D LUT Creator.
- Import the HALD image in 3D LUT Creator.
- Export LUT.
When you do it this way you will also get the HSL adjustments, not only the curves.