OnePlus said that the preview build of Android 11 is best suited for app developers and other advanced users. This is in the interest of providing early access to their community in order to start creating better software experiences.
The company also noted that the OS itself is in its early stages of development, and is not recommended for regular users who have no experience in software development or flashing custom ROMs. Oneplus added that features such as Face Unlock and video calling will not be available in this build, and stability issues are to be expected as well. Those interested in OnePlus’ Android 11 developer preview can find out more via their official website, and can also download it from there. We’ve included the respective links below for your convenience.
Meanwhile, OPPO and Xiaomi have announced that their respective Android 11 beta programs will commence soon, but did not specify an exact date. OPPO will launch the beta for their Find X2 series, while Xiaomi has chosen the Mi 10 series and the POCO F2 Pro for the program. (Source: OnePlus [announcement] [download] / OPPO / Xiaomi [1] [2])