Dynamic Type & iOS Simulator: How can I set the value?

I want to write my UI tests so that they test all seven states of dynamic type, from the smallest to the largest. How should I do this?

Can I set an environment variable for the simulator in my Scheme and then just make different schemes?

Or can I set the dynamic type variable programatically in my test?

I'd rather not make a DynamicTypeController and then make it say what type it is, because I'd risk forgetting to use this for some elements, and then not have the behaviour properly tested.

Cheers

Nik