Team Paranoid Android has just released new builds of Android 11 for the OnePlus 8 and 8 Pro, OnePlus 8T, Xiaomi Mi A3, and Redmi Note 8 / 8T. The Paranoid Android Ruby Beta 2 builds are now available for the OnePlus 8 / 8 Pro and Mi A3, while the OnePlus 8T and Redmi Note 8 / 8T have received Ruby Beta 1 builds.
The Mi A3’s Paranoid Android Ruby Beta 2 comes from XDA Senior Member Vishalcj17. Custom kernels are not supported at the time being, and you must be on the stock Android 11 firmware before migrating. If you run into any hardware related issue, the developer recommends reflashing the stock Android 11 firmware from fastboot. You can find the ROM zip and flashing instructions in the linked thread below.