[pcc]

Yes it's very much mechanically possible to use 2 pedals on the piano at the same time; it's not actually that uncommon.

For organists, these days pipe organs are usually outfit with a sequencer that allows the organist to program a list of registration changes (the combination of pipes/stops used) ahead of time; the organist then advances through the sequence of registrations, by bumping a bumper pedal with the side of their foot, or by pushing a toe stud pedal. Sometimes there are multiple toe stud pedals, which either allow for jumping straight to a specific combination, or for using the closest one as the program advance.

[Doctor_Fegg]

There’ll usually be a thumb piston for the sequencer as well as a foot piston, too.