It is almost impossible to use the gradient editor to simulate blending between lights, because it draws a straight line through RGB space. It would be good to be able to select HSL and LAB colour spaces for the gradient editor, and it would be even better if you could make bezier curves through RGB space, like the free tool at http://www.foddy.net/2010/10/gentle-g... is pretty frustrating that there was more flexibility in Deluxe Paint IV's gradient tool 23 years ago than there is in Photoshop's gradient tool now.
UPDATE! In today's new release of Photoshop we have enabled multiple gradient interpolation options: Perceptual, the new default method: smoothness controls interpolated using OKlab color space Linear: interpolates using linear color space Classic: interpolates using the selected working space. Learn more here: https://helpx.adobe.com/photoshop/using/gradient-interpolation.html Special thanks to @bennettf96052341 for his gracious feedback