All that sounds like it adds much more complexity than swapping out bubble sort for qsort, and the other various optimizations that have been going in to reduce

All that sounds like it adds much more complexity than swapping out bubble sort for qsort, and the other various optimizations that have been going in to reduce boot time. Plus optimizing common code improves boot time for everyone running FreeBSD - routers, firewalls, etc, whereas pooling just helps that one use case. If you can make it startup up fast enough that you don't need any of that extra machinery, why wouldn't you?