any time you cast a healing spell, it uses outbound healing boost. Anytime you get healed, it uses incoming healing boost. If your healing spell heals you, it uses both incoming and outgoing boosts.
If you heal yourself using like a death spell it is only going to be effected by incoming healing. The outgoing will not effect what you receive. If using a life one like fairy or the tree then it is both being used.
it is both; including if your pet heals you (since you are casting Out and receiving In)
life chars tend to use higher outgoing heal stats since they are healing others; a strong hitter like storm or fire tends to boost their incoming heal stats since others on team tend to give them heals.
Incoming boosts every heal you receive, whether from yourself, your pet, or a member of your team.
Outgoing boosts every heal spell you cast, whether from your spell deck or from your pet; and whether you then heal yourself or someone else.
Having both boosted increases your healing power as you cast the spell, then again as you use your spell to heal yourself. So, boosting both incoming and outgoing will give you a double-strength heal when you heal yourself.
If you heal yourself, is it an outgoing heal, incoming heal, or both?
When you heal yourself, it is both.
If you heal someone else, YOUR outgoing and THEIR incoming both affect the heal. Likewise, if someone heals you, THEIR outgoing and YOUR incoming affects the heal.