Currently have a rig setup of

guitar > big muff > Dunlop 535Q Wah > chorus > univibe > analog delay > amp

Whenever I turn on the wah, there is a noticeable (obnoxious) increase in my volume. The 535Q features a gain boost button as well as a volume knob. The gain boost button only worsens the issue while the volume knob does not appear to affect the signal in the slightest. Is there anything that can be done to prevent the unwanted increase in volume in terms of an additional pedal or a modification to the pedal itself?
They don't sleep anymore on the beach..
IIRC the volume control is only active when the boost is on. IOW it's a boost level Try messing with the Q. Some wahs boost the high freq. Maybe adjusting the Q will tame that. Also try a different wah range setting.