Our understanding of spirit healing, as it’s described in lore, is that a spirit healer negotiates with spirits to heal on their behalves, not that they have abilities those spirits boost, if that makes sense—it’s the spirit doing the healing at the mage’s request. (To quote the wiki, “In effect, the spirit healer summons a benevolent spirit through the veil and that spirit uses its abilities on the mage’s behalf.“) Since Cole is never shown to heal anyone in canon and that would presumably be an ability he could use without a mage pointing at who needed to be healed, we’re not comfortable adding that major ability to what he can already do.

Our previous Cole player had similar questions and we believe they ultimately decided that the healing abilities Cole might have as a pure spirit of Compassion were weakened due to the energy required to maintain a solid form, disappear/make people forget him, and the other abilities he canonically has. You’re welcome to recycle that explanation if it helps you!