Using options_.pruning=1 to calculate welfare

Dear all,
I use options_.pruning=1 provided in this forum to calculate welfare under non-liner system, and seemly there are no problem in final results, but I’m not sure whether what i do using the second approximation with pruning.m is correct. Then, i do various loops and make different 3-dimensional plots and contours to check the results with thoretical values in other papers, it seems to occured me that these results are normal. So, can you tell me what I do is correct?
By the way, if I intend to estimate the non-liner system and estimate welfare, conditional welfare and welfare cost, what should I do?

Roger.
Best Regards