"For me as an engineer the whole design is flawed. The ~5mm gaps between halves of the hub allow the plastic to flex. A quick test on this would be to fix the plastic hub to a bench, tie a piece of string around the hub under the lugs and then pulling vertically. You will see the gaps reduce as the pulling forces force the hub inwards in order for the string to pull away. The same effect with a prop. As the dynamic vertical force applied increases the prop forces the 2 halves of the hub to close - and whether or not the lugs are worn, it will pop off. A rapid decent will be the worst case scenario here.
Look, if DJI wanted me to engineer a solution, I would choose the T6061 alloy long before any other material. I have seen some guy (Zac Hary) in the US making copies of the RimTai hubs out of T7075, but T7075 is way too hard for the plastic props and , and T6061 has better all round properties under load."
I hear ya.
And for me, as someone who appreciates sarcasm, "Quick Release Propellers" scores a 10/10.
A Quick Test: you don't even need to fix the hub to a bench to do this test - just pinch the hub with your fingers when it's still connected to the bell housing. You can see the gaps under the hub in the attached photo. This is one of my hubs that developed stress fractures after 75 flights. I didn't catch this before take-off... this was a post-incident discovery.
A Rapid Descent: Yup. One of my props came off, and the Inspire cart-wheeled out of the sky. Fortunately, this was just 30s after take-off, I heard the unusual cavitation sounds, and stopped ascending. My Inspire came down into a tree, which cushioned the fall, and nothing was irreparably damaged. Lucky me.
After having this experience, and then realizing the very flawed design of these hubs (poor structural design, incredibly brittle material) I would gladly shell out some money for a set of CNC'd T6061 or maybe Ti alloy hubs.
The "hub pinch test" will now be part of my SOP.