I think you misread it
trimming = deleting empty data, which is simple zeroes over your ROM
if your WiFI data is damaged by trimming, it means you used the wrong trimmer, because trimmer is supposed to delete zeroes, not WiFI data - I hope you get it
you got recommanded a well-done trimmer, however remember this : zeroes might be in between codes ("libraries") and therefore, deleting the "space" my screw the code, therefore I wouldn`t recommand trimming at all, but buying a larger MicroSD card
examples of screwups
"Hello world"
"Helloworld"