For the gamma issue, I assume the person who made the preset is using different brightness settings than you are. Generally it's better practice to make a preset with the brightness/gamma in-game set to 'neutral' and have the preset do all the corrections, but you can't make people follow that standard.
The lack of DOF is probably due to the depth buffer not being available. ReShade disables access to the depth-buffer in games when they're played in multiplayer. Other times, the depth buffer simply isn't available for whatever reason. The guy making the preset probably plays offline.
-This would also explain the difference in brightness if the preset uses AO, as that'd be lost without depth buffer as well.