I sometimes fantasize about a volume pedal, moreso for guitar than bass, but also for bass. But, I dunno from pedals in general. A google search says things like "a high impedance pedal will work anywhere, while a low impedance pedal will only work with a buffered signal in" and "high impedance before amp and low impedance in FX Loop," but I really dunno.
However, I do know that the Invalid Link Removed will work with your MGT-4 footswitch on the Studio & Stage Rumbles (and Mustang amps). If I ever get ready to put my money down, that's what I'd go with for my Rumble Studio.
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