I use nylok nuts, and would appreciate any reference to an authoritive source which has documented instances of the nylon melting, and allowing otherwise tightened nuts to come loose.
It seems to me that you would have to be dealing with a major electrical fault before generating enough heat at the post to melt nylon, and in that case, tightness of your connection at the battery would be the least of your worries. This is particularly so given the fact that the nylon does not contribute materially to the tightness of the nut, but only to keeping it in place should it otherwise tend to vibrate loose. All the work in a properly tightened nut (believe the standard is 10 ft. pounds) is done by the first one or two threads, which in this application, are stainless steel.
I'm all for bombproofing, but am curious to know if discarding nylok nuts is overkill.