little late in seeing your post
yours runs just like mine
I agree nice locos, and, I broke down and fitted mine with RC despite liking hand on, due to grades-at first two servos, but found only one is really necessary
you may or not know this, but, it is helpful and wise to tighten every screw, even the drivers and the Phillips for the steam chests every time you run
I have one too, and after the first few times, they will tend to loosen up, and, you can actually lose the screws to the drivers as they seem to sometimes work loose
there is one other thing that I find helpful-to remove the burner itself, wrap with stainless steel mesh and secure with SS wire and replace-seems to get a better and more even fire , better pressure and more efficient use of fuel
be mindful that you don't run out of water-only bad design in this loco is more fuel capacity than boiler, and if it runs dry, I have seen some terrible results, blistered paint etc