Seven years after Hong Kong invested and immigrated.

Because as soon as seven years arrive, your ID card will automatically expire. You must apply for permanent residency.

If you don't want to apply for permanent residency, then the Hong Kong Immigration Department will think that since you don't want to apply for permanent residency, you have no plans to settle in Hong Kong for a long time. As you have no intention to settle in Hong Kong, the Hong Kong Immigration Department will not issue any more visas. Because if you don't want watermelon, why do you want sesame?