I hear ya about the newest Thunderbird installs being buggy as snot. I locked my TB install on version 102. Everything after that messes with display add-ins, doesn't work with a couple other add-ins and I hate the way Mozilla has rearranged everything. TB 102 is nice and simple for me.
Thanks for sharing!
i just put my tbird/oauth help file on google drive for reference and to download a local copy if wanted:
https://drive.google.com/file/d/1to4lJPCe1he5Y8Ub6XxYsWjW7HhVI6Xh/view