Oisín's Oath lineage support gem for spells

Oisín's Oath description: Mana Leech from Supported Skills recovers based on Elemental Damage Types instead of Physical Damage
On poe2db this gem supports Spells. The question is, is there any spell that can leech mana from physical damage? As far as I know in POE2 mana leech only works for attacks but spells are not attacks? Has anyone tried leeching mana from spells by this gem and does it work?