Most of my plaques and wall hangings tend to get the ‘picture hanger’ treatment. I like to use the hangers with a free-floating d-ring that secures onto the back with 2 or more short screws, especially with mdf. Sometimes I’ll also drop a spot of CA or wood glue in my pilot holes to reinforce the fibers right before I screw it on. If I need something with a “low-profile”, I might use a keyhole bit to cut a hanger pocket. I haven’t had issues with mdf for either method. But like most things, it will usually come down to what is right for the project. 0.5" MDF can get weighty, so depending on the diameter you’re cutting, plan for more than you think you’ll need.