For my part, it appeared to be specific to an extension for using Apple Passwords instead of the Orion keychain. I can't recall whether it was the Firefox extension of the chrome extension for Passwords integration. I wound up digging around in $HOME/Library/Application Support/Orion/Defaults/Extensions and then deleting the offending extension. Once I did so, Orion fired up nicely.
A crash report in the console for PasswordManagerBrowserExtensionHelper is what tipped me off about the possibility of it being this extension.