I have never put the least bit of thought or effort into frying eggs in cast iron over, say, stainless. It is a better non-stick surface overall. Teflon is gross, do you really want to risk breathing the fumes and eating even more plastic?
FWIW I shrug and use my cast iron.
You just need to let the pan heat up, drop a teaspoon of oil or butter, let if soak in a second then blast it and drop your egg.
More butter more better but that's flavour at that point.
For figuring out if your plans at the right heat, a spalsg of water should bead and float around.
Going that hot with Teflon will give you the Teflon flu.
Only thing I use nonstick for is scrabled eggs and pancakes where a low heat is beneficial.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284091/
I kind of suspect the bizarre health correlation for olive oil relates to its poor temperature range.
For fried eggs you just need to make sure it's hot enough with oil it should bubble and fry without sticking.