How many times can i get a 72 hour visa?

I am dutch and traveling to hong kong. MY flight is amsterdam-london-beijing-hongkong. But 1 week later i fly hongkong-chengdu-london-Amsterdam. Can i get the 72 hours on my way in and out? And if i do, can I stil cross the border hongkong shenzheng with a 5 day special VOA? Also 3 day zhuhai?

Thanks 😊