As related above, superheating increases horsepower (ability to do work at a higher speed with less fuel and water consumption) but not tractive effort (which is a function of steam pressure against the pistons). With 200 lbs of steam pushing against the piston, it doesn't matter if the steam is superheated or not. In fact, if you made a full-throttle start, the steam going to the cylinders is not going to have much superheat in it, as you need a good draft through the flues to draw the hot firebox gasses to heat the superheater elements.
In the case of Knott's and probably the Huck too, the engine would never work hard enough to create any superheat. I never heard the story about why Knott's put new tube sheets in 464. They might have needed to change them because the original sheets were tired with oblong holes and ligament cracks between the holes, or they knew from the start they were going to convert it to a soak and to make the engine steam at all, they needed to remove the big superheater flues. A question someone from the Huck (or an old Knotts employee) is - did the superheater header get removed? It could have been retained and "jumper" tubes made to connect the two sides of the header. If removed, new branch pipes to the steam chests would have been needed - a pretty involved and expensive operation. I would think jumper tubes would have been easier to make.
Let's not forget there was a soak Mudhen in service until 1949 or so. 462 was one of the last engines through the rebuild program in 1930 or so when the plug was pulled on the operation. 462 got her running gear rebuilt with piston valves, but her boiler was not rebuilt and converted to superheat. As such she was identical to 464 in her present form. She spent most of her last years in service leased to the Rio Grande Southern, it seems she gave satisfactory, if not exactly stellar service. There was video released on RGS where the last remaining living enginemen were interviewed. They said the 462 was a decent engine, but you had to stay on top of her and keep the steam and water up. If you got behind on steam or water, it was very difficult to catch up.
Taking the superheater elements out of boiler, installing jumper tubes to the header and leaving the big superheater flues in the boiler does not work. You need the elements in the big tubes to slow down the gasses and create a restriction to impart velocity to the draft. Without that, the draft gets messed up as too much air at a slower rate goes through the firebox. Back in the 1970's the West Side and Cherry Valley removed the elements of Shay #12 and installed jumpers. #12 wouldn't steam for squat. The engine had to be fired so hard that by the time they reached the end of the line at River Bridge, the smokebox was glowing red and the pilot beam was starting to smoke.
