The lycoming starter ring gear problem is not new. Enstroms have suffered the same problem for 30 years.
The mechanism of failure is that while the starter is energised the retard points are active but as soon as the start switch is released, the main points are activated. If the start fails and the starter is unfortunately released at the exact instant the main points open, the engine will kick back while the starter is still engaged with the ring gear. This will either crack the starter housing or remove teeth from the ring gear or both. The only solution, unfortunately not authorised, is to hold on the retard points until after the starter has dropped out of mesh with the ring gear. An old dodge was to put in a manual switch to keep the retard points active until the engine was running and then manually switch across to the main points. This solves the problem 100%. A simple timed relay will do the same job automatically. Kick back is impossible while the retard points are in control.
As this is not a legal mod I'm afraid you got to live with it.
My Enstrom has had 14 ring gears/starters in its 30 year life.
This is not so much of a problem with fixed wing as the momentum provided by the extra weight of the prop prevents the destructive kick back.
Edit. By the way, its much more likely to happen if the starter is sluggish or the battery is down. Keep the timing right as well. Check all connections are good especially the battery and earthing straps. It is more likely to happen with higher compression engines running more ingition advance hence the problem for non turbo enstroms and raven 2s.
And to add a bit more, its not pilot error. Keeping the starter activated for a short while after the engine starts will not harm the starter. There is a clutch on the starter pinion of a B&C to protect it. Activating the starter with the engine running will make a horrid noise but the gears will not mesh so there will be no damage apart from polished edges of the teeth. Not a good idea to do it too much though.
The only thing that will provide enough energy to smash castings and strip gears is a kickback with the gears in mesh. The pilot has no control over that.