Dear @Mario.Ruz,
Similar questions were discussed in the following forum topics:
Replacement for RunNTM? (starting with my post dated July 26, 2019)
Wind & Wave data (starting with my post dated August 31, 2019)
I agree that you don’t need use the interface between OpenFAST and Simulink, unless you intend to change the controller. You can have OpenFAST call the standalone OpenFAST executable (uncoupled from Simulink) directly from MATLAB.
Best regards,