Yes - i have just run a test ...
All files are upgraded and the first site is running smooth - with 1 bug in broken link scanner to be fixed.
But. When i then packed it up and followed my own instructions for upgrading a site i 500-errored the whole thing. I am currently checking to find out why
As soon as i have a version that runs - i will throw it your way and we can all play (you can have this one - but i dont like it when i know theres a fatal flaw to be found still)
(the basic method has been to reverse engineer....let the old build run on php7.4 - go through the error logs, fix the issues 1 by 1 - and onwards ...almost there
)