The easiest way to avoid problems is to change the Schrader valves every 10 years. You also change the valves with new tires for example.

They are not so hard to detect. The only part that makes it complicated is people are not thinking about them. If you have the retrofit kit installed correctly and open the plastic cap and you feel that there is some 'air' pressure while releasing the cap you have a leaking Schrader valve.