If you're got a OnePlus 8 series handset on the Android 11 beta, it's time to check for updates. Android 11 Developer Preview 2 is now available for those devices. To be clear, this is based on the second Android 11 beta, which was released to Pixels last week, but OnePlus is still calling it a developer preview because it's not as stable.
In the firm's forum post, it makes it explicitly clear that if you install this, you're doing it at your own risk, and you do run a risk of bricking your phone. Also, it doesn't work for T-Mobile or Verizon variants, because carrier-locked versions of OnePlus phones don't let you side-load updates.
If you choose to move ahead with it, you can download the image for the OnePlus 8 here and the OnePlus 8 Pro here. You can either download it directly to your phone or transfer it from a PC, but either way, you'll need to transfer the file to the root folder of the device. Once you do, go to System -> System Updates -> Click top-right icon -> Local upgrade, and then select the file you downloaded.