Yes your math is correct but do you really want to burn 120 lbs a day or do you want to heat your home? Yes the stove can put out 70K per day in a perfect lab environment set up on the perfect chimney with the draft set at exactly factory specs that doesn't change. Since I have my stove in manual operation, I can force it to put out twice the heat I have it set for right now but that is not the solution to MY problem.
My problem is air infiltration (leaks) or cold outside air seeping into the house from every knook and cranny, outlet, window, and door. I can force the stove in manual operation to run till burning coals are falling into the ash pan but that won't do me any good unless I can move that heat to where I want it to be.
The measurement we use in the real world is are we warm or not. Not whether or not were burning the right amount of coal.
Don't get hung up on side wall temps and such and concentrate on where is the heat going that is being made. Every setup is different, every stove function is different, every stove puts out what it will depending on the location, the chimney, the air flow in the location, the carbon content of the coal, etc etc etc. Our warmth is determined by how we distribute the heat being produced. The stove can't distribute it, the stove only produces the heat. We have to set the mechanisms in motion to move it where we want it.
From what you posted our homes are similar in square footage, set up, and stove max capacity. I leave the end of the hallway bedroom door open and the window in that room one inch open. That allows air to flow out (hot goes to cold) which forces air flow up the steps and through the hallway to that room. That stimulates air flow in each room and walla we have heat in the bedrooms that have the doors open. I only figured this out by going around the house with incense sticks seeing where the air was flowing.
Find out where the heat is going that is being produced and max that out before blaming the stove.