Suggestion
Add an option to filter for groups that already have an augmentation evoker.
We can use dps_evokers == 0, but that means that we'll never be paired with a Devastation Evoker.

Good suggestion, but hard to implement, because the spec is only availabe as a localized string. This means I would have to map for example "Verstärkung" to "Augmentation" for every language there is in the game. To make it a bit more complicated, German "Verstärkung" can also mean "Enhancement" in case of a Shaman.

So I'm afraid you will have to keep looking at the tooltip to get the exact spec for now.

Now possible in version 5.3.0 by using e.g. augs == 0