Gain Boost Footswitch for MkIIb

[csaws1]

I have a markIIb with reverb and no EQ and was wondering if the jack infront of the power tubes would control gain boost w/ a 2 button switch. The manual is a bit confusing in that it says the jack is stereo if you have EQ and Reverb, and mono if only reverb or EQ. Doesn't mention anything about footswitching Gain Boost, but have seen Gain Boost foot switch listed in old pricelist on the boogie files website. Thanks in advance for any info.