@steeven Update: I followed the advice in this post on another macos thread @nanni61
I moved the /Brave-Browser folder to my desktop and launched Brave. It opened up and behaved normally - naturally none of my bookmarks and prefs were present.
Interestingly - by way of experiment - I quit the browser and then moved my desktop copy of /Brave-Browser back into its original parent folder (overwriting the new vanilla one generated by opening Brave a few seconds before) then relaunched the browser. It opened normally and all my bookmarks and prefs were present.
Baffling. Now I’m back in, can you tell me where I can find the crash ID you requested?