Changing block parameter from MATLAB code seems to need 'pause'?

I'm trying to change a value in a Simulink from my code using the set_param function. I'm using a very simple code:

      modelName = 'Simple_Model';
      open(modelName)

      set_param(modelName,'SimulationCommand','start'); % Start the model

      for i=1:1:10,
          set_param([modelName '/Constant'],'value',num2str(i)); % Change the value
          tic, while toc<1, end; % Wait 1s
      end

      set_param(modelName,'SimulationCommand','stop');

The simulations simply pushes the constant value to workspace variable. However, the simulation ends with no errors but doesn't return any value. I've found out that when I change the delay line from

tic, while toc<1, end;

to

pause(1);

Which supposed to do the same, the simulation does return values into the workspace variable.

Am I missing something? Is there any function to "refresh" the simulation without using the pause function? My actual code require small-to-zero delay, so using the pause function is not an option.

(see code+model attached)