Has anyone tried upgrading to 11.6 yet?

This looks similar to a long standing issue: https://developer.apple.com/forums/thread/678644 In my case, switching to a HDMI cable resolved the issue. Depending on your monitor, you could also try to switch to DisplayPort 1.1 if it supports.

You're not alone... I spent weeks troubleshooting a kernel panic on my brand new top-of-the-line 16" MacBook Pro and eventually figured it was caused by connecting an external monitor via DisplayPort. The crash report looks similar to one of your issues: element modified after free. Apple support is truly infuriating. After a million useless steps they won't accept the blame and just point fingers at "third-party" devices... I mean, hello??? It's just a bloody monitor! As it turned out, I found two workarounds that may help you: 1) use HDMI instead of DisplayPort, or 2) disable DisplayPort 1.2 support on your monitor if possible. Both aren't great options of course as your max resolution may be limited, but it may be better than multiple crashes a day. See this other thread: https://developer.apple.com/forums/thread/678644

Has anyone tried the 11.5 release candidate... I'm not holding my breath...

Just realised one of my Dell monitors has an option to use DisplayPort 1.1 (instead of the default 1.2) and in this mode it doesn't seem to crash my laptop. I'll leave this running for another while to see if it gets around the problem. Of course this option might not be available in more recent monitors and also DP 1.1 is very limiting in terms of resolution/refresh rate (it can't run 4K at 60fps) but for anyone with lower res monitors suffering daily crashes this might be a better compromise until Apple get their act together.

Big Sur 11.5 Beta 5 is out... anyone?

Big Sur 11.5 beta 4... anyone?

Has anyone tested the Big Sur 11.5 Beta 3 release?

Are you connecting your monitor via DisplayPort? Try using HDMI instead - my laptop only crashes with DisplayPort, never with HDMI. Also, try connecting your monitor without the dock (get a USB-C to HDMI cable) to rule out a problem with dock