suggestionss for best 100% Elisp Oauth2 module(s) & config for 29.4 MA-GNUS + mailx + sendmmail please ?

["Jason Vas Dias"<jason.vas.dias@ptt.ie>]

 Good day -

   Google recently wrote me:

         Starting September 30, 2024, Google Workspace accounts will
         only  allow access to apps using OAuth. Password-based access
         (with the exception of App Passwords) will no longer be
         supported.
         POP and IMAP are NOT going away and can still be enabled with
         apps that connect using OAuth.


    Aargh, the reason I got the WorkSpace account was because it allowed
    Admins to emable "Less Secure Apps" to access SMTP2 using password.
    I had installed mailx and the excellent 'sendmail' extension
    and used SMART_HOST and auth and smtp.relayagent and mailertable small
    patches, that select different Gmail or MS-365 SMTP2 mailers and
    use a plain-text (but secret in hidden 'root'-user owned directory)
    'auth' file, compiled into 'auth.db' , this worked fine for my
    Workspace Account, which I got specially to handle my own '@ptt.ie'
    domain name,  mailx or sendmail from command line work fine IFF
    I specify a 'From:' header that includes a known sender in
    '/etc/mail/auth.db' - this used to work.

    Now I have to have some Oauth2 Daemon running constantly to keep
    Tokens up-to-date in Emacs in order to use SMTP , when my
    needed google-chrome-unstable and firefox-developer-edition-v129.8
    browsers are already busy each doing so for themselves !

    What a waste of CPU cycles !

    Please could anyone recommend any good shared Ouath2 Daemon that
    all of Emacs MA-GNUS / IMAP + sendmail + firefox + chrome +
    Google/MS-365 SMTP2+Outh2 could use  ?
    Preferably something that could generate sendmail auth.db config to
    use multiple Gmail and/or MS-365 accounts for mail sending with
    sendmail , and bundle the correct Ouath2 tokens with each send ?

    How would I configure MA-GNUS and mailx / sendmail to use it ?
    I really don't want to have to start a separate Emacs Daemon
    process, as well as 2 separate Browser Oauth2 processes - my laptop is
    busy enough and has slow internet bandwidth usually - can't Firefox,
    Emacs, and Chrome be told to use the same Oauth2 Daemon ? What is it ?

  Thanks, Best Regards,

Jason