After seeing that many HPS lamps have a voltage rise during life problem that damages CWA ballasts? How is it possible for standard American HPS lamps from 150w S56 to 1000w S52 to be safe on CWA ballasts since the ballasts designed for these lamps are all CWA ballasts.

There is no way itmay damage the ballast (until it starts to cycle so wear the ignitor at the EOL).
The US HPS (designed for CWA) are safe on CWA, because they have the positive thermal feedback suppressed by the lamp construction (usually the amalgam reservoir placed further away from the arc, heated up via a thermal resistance of a metal tube or electrode wire, instead of an internal irradiation, with its own distinct heat radiating surface).

Medved can you explain some more on ignitor wear out mechanisms ? What actually happens ?

Medved can you explain some more on ignitor wear out mechanisms ? What actually happens ?

First the capacitor is a component with wound structure and high electrical fields involved. When high current spikes flow, they create high magnetic forces within the structure, causing it to break on fatique after some time. Same from the electrostatic forces suddenly disappearing. Andthere are quite large peak currents involved. If you arecareful, you may locate  the capacitor being one of the "strongest" noise makers there, just behind the transformer/ballast...
Second any avalanche breakdown tends to wear out the semiconductor component (charges get trapped where they shouldn't be, mainly in the oxide on the semiconductor die surface, deforming the fieldsoinfluencing the breakdown there, so the device starts to locally overload, degrading it further till failure).
And whenfirinh, the resistor inside gets heated up quite a lot, so when firing for too long, the heat degrades the materials around (the potting compound, the plastic frame the components are mounted to,...).