Per an email discussion with the owner of the Pro Q products, the legs were failing when a) they were improperly installed and b) the cooker was overloaded with meat. They will not fail under relatively minor weight.
If you dont want to modify the legs (which I personally dont think you need to unless you plan on cooking a lot of food at once), try sliding a cinderblock snugly under the base of the cooker. That will help relieve some of the stress off of the legs.
We cook on 3 PQ E20's and one has the un-modified legs. We have never had an issue with the un-modified legs. I know some people have had issues with the legs collapsing and I would bet $ that overloading, improper leg installation and/or uneven ground had a hand in the leg failure.