Start values of states are hardly changeable

[Rüdiger Franke]

The attribute isValueChangeable is true for state variables, even though Modelica insists in initial values, like in the following example:

model IsValueChangeable
  parameter Real x_start = 0;
  Real x(start = x_start, fixed = true);
  Real y;
  Real z;
initial equation
  y = 0;
equation
  der(x) = 1;
  der(y) = 1;
  der(z) = 1;
end IsValueChangeable;

Doesn't this mean that start values of state variables are hardly ever changeable?

See also the level states in Modelica.Fluid.Examples.Tanks.ThreeTanks.