OnePlus sent out the first OxygenOS 11 (based on the Android 11) to these devices ahead of schedule, pushing out yet another update in the meantime. Now that we see the third update in this series, we know that the company is working really hard to make sure the unit gets the stable build as of the right time.
The new OpenBeta is geared towards background process optimisations to improve battery life usage, improving the Work-Life balance feature and bettering the situation where VoWiFi was having some faults. Overall, the update contributes to system stability and offers other performance improvements to match.
The over-the-air update weighs about 191MB so it is not too much on the heavy side.
With Android 11 having been in the market for almost a year, and Android 12 coming out soon, it would be better if OnePlus got this done and shelves out the update asap.