Cool! Does PLECS do any symbolic simplification for its equations? Without that step, we found it impossible to handle even the smallest examples for realtime audio circuit modeling.
On the SPICE side of PLECS Spice, we also perform this kind of reduction for some components if we can, using graph algorithms. For instance, a basic SPICE solver would use a zero voltage source as an ammeter, which adds not only a current variable, but also a nodal voltage because the element has two terminals. Currents can be bad for Newton's method, because they have a very different scale. Often, we can completely avoid this by computing the current from surrounding components. But SPICE is very far from anything real-time.