Hi,
the fourierspacing values affect the accuracy of your calculations. As general rule to evaluate the fourierspacing one can use [cutoff value]/8. A value larger than this will makes the calculation inaccurate.
My suggestion is to use the simulation you ran to have an idea of what is going on in the system, but not for data production (e.i publication). Then I will rerun the simulations with a smaller identical fourierspacing.
Best regards
Alessandra