Finally migrated away from UEVENT_HELPER to netlink-based solution on my #Linux boards.
"... should not be used today, because usual systems create many events at bootup or device discovery in a very short time frame. One forked process per event can create so many processes that it creates a high system load, or on smaller systems it is known to create out-of-memory situations during bootup."
That text was from 2010 but it took till 2025 until my 32 MB #ARM systems failed.