I occasionally run into a situation where my prints have good midtones and shadows, but the highlights lack detail (though the detail is in the negative). I know that in many cases, I could burn those areas in (which is what I normally do), but in some cases, the shapes of the highlights are rather too complex to burn, and the exposure needed is ever - so slight that burning would have to be very quick. Is this a case where pre-flashing the paper may be us use? If so, does anyone have suggestions for methods / times? (I'm using Ilford MGIV and Kodak Polycontrast for my paper).