Other Expose-like behavior in window managers

Do you mean that you found a bug report but lost track of it?

KWin has never been so crash-prone for me as it has for you. Here: latest packages, FreeBSD 14.0-CURRENT.

Actually, I mean KWin has never been as stable for me as it apparently has been for you. :) I have had occasional crashing of KWin from FreeBSD 9 through 12 over two different machines and many ports revisions. When it started crashing more frequently, I abandoned it.

I am not able to move to CURRENT at this time.