20 Ritual Limit - Vengeance vs Enchant

[Feldor]

I've looked through the 2.0 rules and ritual descriptions.

A specific item may not contain more than twenty Rituals. Some Rituals that can increase effects on a specific
Ritual may count as more than one Ritual towards this twenty Ritual maximum. Note that this counts all Rituals on an
item; an item may have multiple batches of Rituals each with their own tag, but the total number of Rituals may not
exceed twenty.

As with items, individuals cannot possess more than twenty Rituals on their Spirit, including such rituals as Regenerate, Vengeance, and Spirit Link. If the individual dies, some Rituals may expire upon resurrection if they were placed upon their Body.

And the lines from vengeance ritual mentioning charges:

This Ritual has a number of charges equal to half the number of levels of Formal Magic possessed by the Caster rounded down.

Out Of Game:
Note that if this is Spellcrafted by a character who does not possess Formal Magic levels, it will result in a functionless Vengeance (with 0 charges inflicting 0 damage).

How do I know what rituals that give multiple charges do count, and what rituals don't? Why don't Vengeance charges count against the 20 ritual limit, but Enchant charges do? It really seems like Vengeance should cap at a maximum number of charges as that will fit on your spirit under the 20-rit limit.

 

[Polare]

Vengeance is the only exception to the rule.