Validation of arrays of arrays using ember-changeset-validations

I'm using ember-changeset-validations together with ember-form-for and it works perfectly, so thanks for that.

Currently, I had to handle a situation when my changeset contains Ember.A() which contains ordinary arrays of primitives. Validations are automatically executed when the top-array is changed but changes inside of child-array are not seen from ember-changeset(-validations). I have created a separate key in changeset (_NAME_index) which matches the content of top-array and it executes the validation (as 'set' is caught as normally).

Is there a better way how to do it?