Great thread idea! I think technological and scientific advances have made certain halachos subject to re-examination. IN E”Y, I have heard there is a “kosher phone” that technically is not mechallel Shabbos when used (it is used for by doctors, I am told). We have the kosher lamp that can be shaded (which effectively renders it turned off), and kosher alarm clock. The simple Shabbos clock timer, that can turn lights on and off is an example fo something not in use during the times of the early talmudists.
We now have halachos pertinent to in vitro fertilization, genetic testing, organ transplant both from cadavers and live donors. These things were not done centuries ago, because the technology did not yet exist, though our chachomim did discuss many things in the Gemorah, that we now know of scientifically, today.
Halacha (ACTUAL halacha, not chumros upon the chumros), does not change with time. Our need for interpretation of a specific halacha might be necessary, as we learn things that seem contradictory at first. The laws related to Chalav Stam are a good example. We know that in the USA ONLY cows’ milk is stamped USDA Grade A milk. Therefore, it is not halachically necessary to have a chashash that the milk is mixed with unkosher animals’ milk, because such milk is not used and certified in this country. That being said, many still prefer to only use Ch”Y and i respect that (I domn’t want to turn this into a Milk discussion again, it’s been done to death in the past). So if in European Shtetls it was NOT acceptable to drink Ch’St, it might have been because there were no strict controls and mare and pig milk were also drunk by the goyim. The halacha is that the milk has to come from a kosher source and where it cannot be verified, only Ch”Y is permissible. That halacha doesn’t change. But the interpretation of acceptable guidelines in different places, might cause a re-examination of that position elsewhere.