I agree it is a limitation if you can only play minor an major chords. But you would have both hands available at the keyboard to compensate for that. Most important is that the accompaniment doesn't sound off. A major chord would sound off when a minor is required. A normal chord wouldn't sound off when a 7th chord is required, it might sound like something was missing and you can add that on the keyboard. I think it would be complicated trying to play all kinds of chords with your feet. You can form all chords with your right hand because there are 5 fingers there, but you only have two feet.
JM