Unfortunately Ive spent a number of years working with warranties in the motorcycle business,and its difficult on both ends to say the least.
That said yall gota remember that a manufacturers warranty only covers manufacturers defects in most cases and is not a service or repair contract.So the warranty does not cover wear and tear or broken parts from normal use.That said some manufacturers replace parts regardless of use.Just depends on the individual your talking to or the company your dealing with really.
In my experience any manufacturer worth their salt will take care of a early parts failure or manufacturing defect regarless of expressed or implied warranty or age of the weapon....and in the case of DD and BCM that is not a concern...they stand behind the stuff they sell 100%.LMT is the same way.Top notch folks all around.
The key is to buy "known quality" parts and assemblies that have a reputation for heavy use durability.If you do that you reduce the failure rate and insure that the weapon retains a respectable service life.But hey nothing lasts forever,when its worn out its worn out and time to buy another.
HTH