Most institutions prefer to hold onto RMB with the expectation that it will rise in value against eh USD and in any case, they can use that RMB to buy products from the worlds factory: China.
Other currencies can also buy products, money primary purposes is to be a medium exchange of the whole nation. The currency values can't be fluctuate as it would directly harm people livelihood and industries which allowing too much RMB to circulate outside control decrease ability of pboc to made currency stable. Autarky should be the aim while allows international trade to continue.
This is actually a very interesting subject, because there's a pretty close correlation between high level of rice consumption in East Asia and high IQ in the region. Of course correlation doesn't imply causation, it could also be the use of Chinese derived logographic languages which induces greater ability to handle abstractions, or just good old race.
I remember hearing talk about having two currencies one for onshore RMB with capital controls and another for freely floated for offshore transactions. Maybe the plan is to use the HK dollar maybe rename it the Chinese dollar and keep the Chinese yuan for domestic use? I maybe off base here.
Watermelon rinds are great in stir fry.