Can the witch hex "Gift of Consumption" be combined with Fortitude (Harmless) spells?

Question

The description of the Gift of Consumption (Su) hex says:

The witch curses a creature to share any effects that target her vitality. Whenever the witch is exposed to an effect that requires her to attempt a Fortitude save, as an immediate action she can curse a creature within 30 feet to share the effect. The hexed creature must also attempt a Fortitude save at the same DC as the witch’s, and on a failure it is subject to the same effects as the witch. Regardless of the outcome of the saving throw, the creature can’t be targeted by this hex again for 1 day. This hex does not function with effects that require additional types of saves, such as phantasmal killer.

The Greater Gift of Consumption (Su) hex description says:

The witch can more effectively redirect effects to her proxy chosen by the gift of consumption hex.

When the witch succeeds at her Fortitude save against an effect that she has redirected to a proxy, the hexed creature takes a –4 penalty on its Fortitude save against the redirected effect. If the witch ever fails a Fortitude save or intentionally exposes herself to an effect that requires a Fortitude save, such as by ingesting a poison, she can redirect that effect to affect only the hexed creature, though the hexed creature can still attempt a saving throw to resist the effects. Once she has redirected an effect to another creature in this way, that creature cannot be affected by the gift of consumption hex again for 24 hours. The witch must have the gift of consumption hex to select this hex.

Can the gift of consumption hex be combined with beneficial effects, such as the spell "Delay Poison", which has Fortitude (Harmless) in its save descriptor, and target an ally?

Does the situation change if the witch character has Greater Gift of Consumption?

Answer 1

No, Gift of Consumption cannot be used to share harmless spells.

From the PFSRD (emphasis mine):

(harmless): The spell is usually beneficial, not harmful, but a targeted creature can attempt a saving throw if it desires.

From Gift of Consumption (emphasis mine):

Whenever the witch is exposed to an effect that requires her to attempt a Fortitude save, as an immediate action she can curse a creature within 30 feet to share the effect.

Gift of Consumption can only share effects that the witch must make saves against. Greater Gift of Consumption also uses the word "requires". Harmless saves are optional rather than required, and therefore effects with harmless saves cannot be shared via Gift of Consumption.

Answer 2

Spells typically can't be shared using the gifts of consumption

The hexes gift of consumption et al. mention "an effect that requires [the witch] to attempt a Fortitude save" (emphasis mine). Because a "creature can voluntarily forgo a saving throw and willingly accept a spell's result" a creature is typically never required to make a saving throw against a spell. That means, for example, a witch can't share a delay poison spell using the supernatural ability gift of consumption: the witch had a choice whether or not to make a saving throw against the spell and because that choice was available the saving throw against the spell wasn't required and the gift ability doesn't apply.

This reader assumes that this is why the hex greater gift of consumption specifically mentions poisons. While it's a common house rule to allow creatures to voluntarily fail their saving throws against anything, creatures typically are required to make saving throws against diseases, poisons, and other nonspell effects even if for some reason they'd prefer to fail those saving throws. It's these effects that require saving throws—if they're Fortitude saving throw—that the hexes gift of consumption et al. can redirect.