I do not think it makes the part retain heat more. It does get hot buffing. enough that beer explodes you have to cool it off a few times while doing a can.
Some of the cans were dented so I had to dispose of them. Here is an Eddie Air Gap I polished right before I was told I had cancer. I got a great deal on it and thought I might need it to do a Fuel Injection one day.
I was told do not to paint or sand so stopped. I have all clear now but doing the whole enchilada of protection on now.
Before I was just chugging away at anything I saw that I had here that I thought would look cool shiny. Even the Right Angle Oil Filter Adapter
Miles of Stainless Trim for others. And some fur me.
3 timing covers sanded polished and triple plated 2 oil pans, the list goes on. Chrome is cheap if they do not have to do the work. Or just plain old as the Brits say "Al_You_Min_I_Um"
Looking around last week M/T valve covers I had since age 17 that used to be black.