The tsugi, tsugi-php, koseu-php, and tsugi-build master branches are all PHP 8.4 and all my Tsugi servers (including the very busy
www.py4e.com) are on PHP 8.4. I have ubuntu 22 and ubuntu 24 systems running smoothly.
I have made a few scripts that upgrade PHP 8.2 -> 8.3 and PHP 8.3 -> 8.4 without a fresh install. I uses tese scripts on ubuntu 22 and 24. You might find them useful.
Let me know if you notice anything.