Stress concentration
Yes it is tedious. Yes many people don't do it. Yes it helps lower stress concentration and fatigue cracking.
I have an aircraft structures background and the detail on the rolled AN hinges are pretty poor. Sharp corners and and the edges are rough with burrs.
I would do it and for me personally, buy the expensive extruded hinge for the aft bottom cowl sides. This location, even though they use the larger sized rolled hinge, never lasted for me, a few hundred hours. The extruded stuff is much stronger, better material and there are no sharp corners or burrs out the box.
Is it worth it. It can't hurt and hinges are sometimes known to fail. I think it has more to with pre-stress and poor installation and poor attachment than it does the burrs on the hinge. However you would not build your plane like these rolled hinges. Look at them, they don't follow the normal smooth, no burr, sharp corner rules. Than again they are meant for low stress applications. Again with air loads, vibration and pre-stress from installation can certainly cause them to fail. Since vibration and fatigue life is affected by stress concentrations you could improve life. However there are some tricks to keep the stress to a min. One is to off set the center line of the pin from being exactly aligned with the joint (halves of cowl). George
George