from what i have seen on here most aare changing with the sylvania bulbs, including me. no melting or other mods happen with the sylvanias.
I dont know about LED ones, but i doubt they will melt the lenses. dont halogens or whatever the sylvanias are produce more heat than LED ones? As i said i dont really know this is just my uneducated opinion.
by the way, where are you planing to buy them from, if its online can you post the site i would like to take a look? thanks