I am a bassist and have several EHX effects. My question pertains to the wiring/functions of the distinct pedals. I will be getting the new Memory Boy and I am considering purchasing the Boss FV500H (high impedance inst level) volume/expression pedal. It has 4 connections-input, output, an expression output as well as a seperate tuner output on the side with an attentuator.

My pedal chain is as follows:
Volume-Tuner-Compressor-Bass Fuzz-Small Clone Nano-Bassballs-Holy Grail Nano-Micro Pog-Memory Boy

When engaging the expression toggle on the MB, will this negate the volume function of the FV500?
I like to cut volume after a song is completed! I may assume that as currently wired in my pedal chain- the FV500 volume output cable runs to the tuner and through the other pedals, where as the expression output of the FV500 will be connected directly to the expression input on the Memory Boy.