Spell Penetration and Healing

Reverb

Can anyone help me understand how Spell Penetration affects healing party members? Is it worth speccing for on a character that is built primarily to heal end game group content?

Lightspeedflashb14_ESO

Spell pen has absolutely no effect on healing. Just max magic, spell damage and spell crit matter.

Spell pen only matters to dps, so if you intend to dps, then it matter.

Beardimus

Does anyone know if Heals over Time (HOT) are effected by DOT boosters? Such as Thaumaturge etc. ?

Lightspeedflashb14_ESO

Heals are not effected by that. The only CP that directly impact your out going heals are blessed and elfborn for crit magic heals and precise strikes for crit stam heals.

Autolycus

The only time penetration will affect your healing output is when your healing scales directly off of the damage dealt, as is the case for Nightblades with Swallow/Funnel and Sap. Radiant Glory (Templar) heals based on damage dealt as well, so in this case penetration would supplement healing. But when it comes to pure healing skills - i.e. all Resto Staff heals, BoL, Twilight Matriarch, Cauterize, Obsidian Shard, etc. - penetration is not going to be of any benefit.

Edit: There is one exception for Resto Staves: Doing a fully-charged heavy attack will heal a nearby target, and this heal is based on damage dealt. So when it comes to resto heavy attacks, more damage = more healing. Penetration would affect this, and so would Infallible Aether. Unless I've missed something, however, this is the only Resto Staff "ability" that will be effected by penetration.