In which circumstances would you prefer to use mode_compute=6 rather than the other mode_compute options in estimating a DSGE model?
Can one be more sure to get closer or even at the “global optimum” with mode_compute=6 as compared with the other esimtation options?

monte carlo optimization routine (monde_compute=6) is not an optimization routine, or a very inefficient one… so, nope it doesn’t gurantee you that you’ll get to global minimum, and I don’t know even if you should hope… you can read more on it at dynare wiki… usually mode_compute=6 is used when other optimization routines fail to provide an optimial value with a positive definite hessian matrix.