Except it's not a complete non starter is it? Because you're taking you time to post on a thread about a pedal that actually exists and is selling well for bass players that uses pitch detection to drive a synth engine.
Is it a solution for every case, obviously not. Is it the perfect solution, clearly not for the reasons you've just explained... yet here we are with other people working around the limitations and bending the laws of physics.
Some folk will decide the MXR is the perfect flavour for their band, others will use something else, or will use keyboards, or in your case you will skip synth bass sounds as you don't have space for a keybords or want to use pedals other than your multifx unit, and others will have no interest in synth bass whatsoever... the point is different people will come to different conclusions and decisions.
Someone who owns the pedal the thread is about and giving opinions on how it tracks on "does your mother know" is far more interesting.