See the last comment on https://tickets.openmrs.org/browse/RESTWS-306 for my thoughts on the non-ugly way to fix this.

(option 1) let resources define "deferredProperties" or "priorityProperties"
(option 2) change org.openmrs.module.webservices.rest.web.resource.impl.BaseDelegatingResource#setConvertedProperties so it iterates over allowed properties and sets the passed-in properties in that order.

Think you have time to do this now/soon?