Plug normally doesn't make the ball crack. The ball will crack around the plug. Regardless, if done correctly, plug will last the life of the ball. However, if your ratio of plug to hardener is off the the plug will crack out. Example, too much hardener, or too much mixing of your filler and hardener will do that.
Storage should be in a room that will be unaffected by outside temperatures. Or you could leave it unplugged and plug it when you decide to drill it.
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