In my experience, gear collapse is almost exclusively mis-rigging and poor or non-existent maintenance and why the gear needs to be looked at by a knowledgeable Commander mechanic. Bungees arenít holding the plane up. Obviously they help pull it over center particularly important if in case of hydraulic pressure loss. Itís an extremely robust main gear compared to many planes (such as Twin Cessnas) but parts under load wear and thatís why there are scheduled gear inspections, clevis inspections, etc. Looking at many piston Commanders itís amazing to me how many show no evidence of a real gear inspection in the last 20+ years yet still do their job. IIRC, itís 3,000 hours but No calendar limit in the 50ís/60ís maintenance manuals. Given the 5 year interval on 690 series, I think it prudent to check the gear adjustments and look for cracks/corrosion every year. Itís just not happening out there.
As a practical pilot suggestion, I recommend a wipe down of the actuators and oleos every pre flight. I use lemon pledge. Learned that from the most respected forestry operator. Works well and smells good.
If you see any drips off the actuators, itís time for immediate maintenance. If you let them get dirty and roll an O-ring, you lose pressure. Then you really need that nitrogen pressure and those bungees!