Easy solution: Iatric [Effect] is only Divine; make Cosmic and higher versions of it. We even have templates for how the magnitude should change, in the form of Divine [Effect] -> Cosmic [Effect] -> Transcendental [Effect]. The existence of Ultima [Effect] also suggests that you could do a "repeating" version at the next higher tier, such as a Cosmic version of Iatric that is exactly like Iatric except that it repeats for [Divine Rank] rounds.
We did similar things in my game when we started to seriously get into divine rankings above 4, because the players were noticing all kinds of gaps in their available choices. As a somewhat complicated example, we've had house rules for what I call "advanced energy" types for longer than I can even remember to tell you, which are considered essentially equal in value to Force (in point of fact, Force is one of the types). An example of one of the other types that everybody's game has is the type called Disruption, which is defined as being "the energy type that Disintegration uses." Now, long ago I made an Advanced Energy Substitution feat that lets you change the energy type to one of the advanced types, at the cost of a +1 spell-level bump; this means that you can (with AE Substitution (Force)) change a Fireball to a Forceball at the cost of making it 4th level. Now, Ascension gave us Energy [Effect] which deals d6 damage per HD, and Force [Effect] which deals d4 damage per HD; since my game featured Force as merely one of several more powerful energy types, it was an obvious extension to just say that Force [Effect] is really just one of the Advanced Energy [Effect] types. So in my game, gods can take Force [Effect] if they like, or Disruption [Effect] which is identical except for dealing Disruption damage instead of Force.
My point here is, don't treat the system as an absolute- it's better to treat it instead as a base for jumping off and making the stuff you need. Ascension's math is very elegantly set out and tends to be quite internally self-consistent; this in turn makes it relatively easy to extend.