I use custom transformation in one of my model like this:
App.Question = DS.Model.extend({
questionName: DS.attr(\'string\'),
parentQuestion
The transformations don't get applied except on find/save.
The problem is ED doesn't know how to track your pojo living on your record, so it doesn't show up as a dirty attribute, unless you changed the entire pojo, not just an property on the pojo.
You might consider making it into some relationship, or non pojo data type