Hi, Gary!
Looks interesting. Something similar I was going to do with Scatter-Gather to parse aggregator and recepient-list. 
And I understand why you do it here, not in the instance class: there are many attributes to parse.
I don't rember where I saw something similar (S-S ?), but if we conclude that it is legally, so take it to adopt! 
However shouldn't it be wrapped with `BeanDefinitionHolder`? Does `BeanFactory` autowiring work in this case?