A little background:
In the early 1700s the Dutch East Indies saw huge waves of Chinese immigration. Batavia (Jakarta) was essentially a Chinese colony with the entire economy ran by rich Chinese merchants and labour guilds. It was getting to the point that the Dutch felt they were losing control of the place.
The Dutch governor decided to round up the immigrants and ship them off to Ceylon as plantation slaves. When word got out that the captives were being dumped at sea the Chinese community revolted. What followed was the Batavia Fury of 1740 during which 10,000 of the 100,000 Jakarta Chinese were killed. The massacre dispersed the rest of the Chinese population throughout the East Indies, but did little to end Chinese immigration. VOC was shocked and imprisoned the governor and the Chinese economic activities resumed in Batavia. By the 18th century the wealthy Chinese merchant class had became Christians and behaved "more Dutch than the Dutch."
What if in 1740, the Batavian governor decides to settle the Chinese population in Australia instead? The place was know to the Dutch but the VOC lacked the energy to colonize it. With the excess labour market they could turn Australia into a profitable enterprise.
Dutch Australia would then be populated mostly by Chinese but governed by the Dutch and managed by the increasingly Dutchified (is that a word?) Chinese merchants. They would become Christian, Dutch speaking colonies based on Dutch law. This could turn around the Dutch Empire's declining fortunes in the 18th century. Not only would the colonies be wealth generating, but it could result in the VOC gaining considerable market in China itself through its contacts with China through its Chinese-Dutch subjects.
Having large numbers of Westernized Chinese trading in the ports of south China would undermine the closed markets of the Qing Empire. It would lead to expanded ties with the East Indias/Australia, and to Europe itself. A growing Chinese bourgeoise would form and become influenced by Dutch ways. Ultimately this cosmopolitan middle class would destabilize the Qing regime.
.