You have grayscale gradient from 0 to 1. Now you turn values within 0.05 to 0.9 into 0 to 1 range in red channel, values from 0.075 to 0.95 into green channel, and values from 0.1 to 1 into blue channel. There is one more trick you can pull. You can sample the texture only twice, and the take the difference between two samples and treat it as shift in value from central channel to missing channel.
Method from Deathrey. Texel Size is "Texture Property" node using texel size as chosen property.
Unreal Engine's Rotator node uses radians. Remembering that a 360 degree arc (circle) has 2π radians in it, if we use Pi as our input we can exactly figure how much rotation to use on a material. In the example above (left), we are rotating the material by 1/4, or 90 degrees. In the example on the right we are rotating the material by 1/2 or 180 degrees.