Weeks ago someone posted an article with a tip from professional chefs where the secret to getting the shells to fall right off hard boiled eggs was to boil the water and then put the eggs in. The temp shock does the trick.
Baking soda in the water helps too.
That’s the way I do it. Bring water to boil, drop in eggs, boil for 15 mins. Works every time.
You get cracked leaking eggs that way with the leaking whites poached out streamers...nasty.
Start with cold water just covering eggs in pot bring to boil, remove from heat keep lid on and lest rest for 7 mins, remove eggs and plunge in iced water, THAT’s your thermal shock right there, let them cool down to touch...hardboiled eggs ready for whatever.
Also, to make for easy peeling, with a pointy knife poke a small hole in the big end of the eggshell (diaphragm end) before boiling.