I like reading misc@ mostly due to the constanst BUTTHURT that is going on here.
But seriously though, each program can change it's own malloc flags either by calling setenv(3) or just by updating static malloc_options variable. So there is really *NO* difference between your old way (/etc/malloc.conf) and your new way (setenv MALLOC_OPTIONS). There is a possibility that a program will reset it's own env, but it would most likely not.
