Pretty much all the market "High Omega 3 Eggs" are produced by feeding the chickens flax seed meal. I think it's well known that the omega 3 from flax is absorbed poorly by our body and is inferior to fish oil in every aspect. So is there some catch to omega 3 eggs? Is the omega 3 content only an "on paper" attraction, thus consuming them is equivalent to consuming flax seed along with commercial eggs?
Recent studies suggest that in order for an egg to have an omega 6:omega 3 ratio close to the 2:1 that is thought to be favourable according to Paleolithic principles, the hen producing the egg would require a special feed beyond that of simply being free range. A 2009 study found that "omega-3 enriched eggs" contained an omega 6:omega 3 ratio of 2.27:1, whereas both "organic free range" and conventional eggs maintained a ratio of 10:1 (Samman et al. 2009).
Other studies have mentioned that the nutrient composition of the egg varies greatly with the feed given to the hen, and that consuming eggs modified to deliver higher amounts of omega 3 fatty acids "may lend a health advantage" (Shapira et al. 2010, p. 273).
Additionally, in response to your idea of absorption by the human body, I agree with the comment above that suggests the chicken does most of the processing. Ferrier et al. (1995) and Oh et al. (1991) both demonstrated that consumption of omega-3 fats from eggs were reflected in the blood profiles of humans - suggesting their easy assimilation. In fact, chickens are thought to be great 'factories' for making nutrients bioavailable to humans (hence the wealth of literature suggesting all kinds of 'designer' eggs rich in antioxidants and such).
Anyway...enough of my rambling...all of this was just to say that I believe that there is an advantage to omega-3 enriched eggs simply because they pay attention to the feed given to the hens above and beyond simply letting them be free range. So the research suggests that it is more than simply an 'on paper' attraction as you suggest.
I get so frustrated with Flax. Lets be honest, flax really damages some people's health. Its been pulled from the market before. For some its extremely inflammatory. My own experience, and I've tried every form of flax I could find, is debilitating low back pain. Not understanding the link quick enough put some serious mileage on my back.
I'd like to see flax pulled from most products. The farmers that grow it can grow something else. The smallest amount of it in a product and I get back pain. Often make urine smell strange. I know I am not an isolated case, its a dangerous food that should be regulated.
Part of the problem with it, is that it boost the numbers of Omega 3 on boxes in the cheapest way. Chia would be a better substitute.