Over the years there have been a bunch of different session lock related optimizations to /mod/hvp/ that broadly should be re-done in /mod/h5pactivity/ and which are causing pain for a few of our clients. Specifically embedding a file:

h5p/embed.php

was fixed in its parallel issue here:

https://github.com/h5p/moodle-mod_hvp/issues/344

There are a bunch of similar code paths which have been improved here

https://github.com/h5p/moodle-mod_hvp/issues?q=is%3Aissue+session+is%3Aclosed

If you grep for \core\session\manager::write_close there is zero session stuff in either /mod/h5pactivity/ or in core libs in /h5p/

So at minimum it would be good to side port the embed fix, and even nicer would be to audit the various other session improvements and side port them so we don't have to find them all again the hard way in prod with clients.

Some of these issues are exacerbated when in conjunction with a remote file system like tool_objectfs.