Does it really matter if the background processes use less than 64 MiB of RAM? RAM is cheap (even though Apple seems to sell systems with severely limited max RAM).
In addition, the OS is often tuned to aggressively trim RAM usage by background processes - so the actual usage on a busy system is far less that you see when you look shortly after rebooting.
Trimming something that's using less than 64 MiB won't give a noticeable boost.
Exactly