Svarogs assist is ability damage. Elaborate are the ability damage weapon skills, though (besides them being rather terrible) I don't think there are any good fire weapons that have it as 2nd skill /3rd skill as of yet. Could be wrong though. People could potentially run Hephaestus, who has a 30% buff too.
Ofc you wouldn't aim for ability accessories, but given how common they are, you're bound to have some of them in your 5 acc slots. All that adds up in the end.