Here is what I found:
Lift-up Cabinet doors. Heartland customer service called back and was very helpful. Apparently, my unit was built during a short (a few weeks) period when these lifts were not being installed. They have since gone back to installing them on new units and will cover mine under warranty for all 12 doors.
The issue of added stress on the hinges was answered too. If the piston is installed so the door is open 90 degrees or more, there is more stress than if the piston is mounted and the door is allowed to swing open less than 90 degrees. When there is a hinge problem, they fix it using an epoxy to reinstall the hinge, and with the epoxy it is stronger, there is no more problem.
FYI