Using a totally stock setup I've broken or cracked multiple rocker shafts with fairly low performance hydraulic cams and the associated springs. It's always the part of the shaft at the end that is cantilevered out there for the 1, 4, 5, or 8 exhaust rocker. On the dyno mule I did for my Car Craft build, and used for the 390 stroker dyno mule in my book, I used stock parts but added the end stands from Precision Oil Pumps. Never any problems with that valvetrain, and that was with a .640" lift solid cam and springs that were about 400 pounds over the nose.
My opinion is that rocker stands that support the end of the shaft are essential if you are using stock rocker shafts. But on any serious build I also upgrade to heavy duty shafts, rocker arm spacers (instead of the factory springs), and a roller rocker arm.