I fell behind on my macOS Big Sur and Monterey beta releases. I just installed macOS Big Sur 11.5 Developer Beta 4. Furthermore, I am sure Big Sur will not be updated past a version 6 like most other Mac operating systems. Big Sur Developer Beta 4 is very snappy, everything seems to work well. I am looking forward to installing it on my main machine soon. Beta 2 of macOS Monterey is still pretty buggy, just have to wait and see how that goes.