[bloat]

In my opinion it is dependent upon the specific angelfish...one flame may nip right away....and another one may not for months or years...
That being said.... If you have LPS there is a likely chance they will become a snack at some time. It may not happen right away...but eventually it would be a tasty treat for them. Specifically if your keeping pricey fleshy LPS like Acans, brains, flowerpots etc I would advise against it.

The only true really reef safe angels that I have ever kept my experience are the Genicanthus species.

Any fish can break the norms and feed on corals on occasion though. I have had even yellow tangs and blennies nip on coral and clams in the past.

If I was to stock a reef tank with LPS or SPS again, I would not add an angelfish outside the Genicanthus species.