+ flat damage mods

The mods which add dmg to

Smite and otherwise unbuffable dmg instances.

We all know Grief.

Today, I've stumbled upon

Ghostflame. Imo it is "same" mod as Grief's one. Did not confirm tho.

Are there any other items with such mod?

Don't forget that dmg from stuff like

Ghostflame is a "magic damage" while

Smite uses physical and flat physical dmg affects it the most (because of how broken calculation multiplying is for them).
Another decent weapon (can't compete with Grief tho but can be used as budget options) would be something like

The Redeemer,

Windforce. Then also exist some others like

Astreon's Iron Ward,

Doombringer,

Stormrider,

Fleshrender,

Magewrath,

Buriza-Do Kyanon,

Hexfire,

Headstriker, etc. and some with little bit of it like

Stone Crusher,

Lightsabre,

Butcher's Pupil,

The Minotaur,

Kelpie Snare,

Hone Sundan,

Spire of Honor,

Moonfall etc.

Ghostflame doesn't add anything to

Smite as

Smite doesn't work with +magic (nor any elemental for that matter).

Also doesn't work with +min or +max.

You do need actual flat phys +dmg.

Grief, Astreon's, Redeemer, that sort of thing.

Even

War Traveler has it. Just check damage +number.