I took some care with the more recent ‘updates’ to not interfere with the ‘default look/feel’ if a new functionality is not enabled. Some older changes were related with auto brightness corrections of scanlines (they aren’t implemented atm.), which could require a bit of more fine tweaking.
Grade with it’s default settings could produce a gamma deficit if an extra crt shader with gamma options follows in the chain. So one option could be to even both grade’s gamma to a single value or to compensate with the crt-shader output gamma. Input / Output crt shader gamma of 2.2-2.5 is sortoff the best option, since Grade doesn’t stay in linear space.
In more recent versions of ‘GDV’ ‘Gamma correct’ and ‘Mask gamma’ are introduced. First is a nice compensation option if strong scanlines, trinitron masks and slotmask are used at the same time (for example), which leads to stronger brightness loss, especially on dark pixels / areas. Mask gamma more or less determines the distribution of intensity of masks over the spectrum and is less related with the above mentioned problem.