An o ring on a din can not fail at depth if the first stage is bumped on something however a yoke o ring can blow out in a heart beat if the first stage is bumped on something & extra pressure will make it much more prone to fail!!!!!! There is a reason tech & public safety divers dive din even on low pressure because it is safety!!!!! Anytime I can do something to make myself safer I do it!!!!! I choose to live to dive another day & not take unnecessary risks!