The percentage of users of FileVault on OS X It must be quite small, but that is as true as that small portion of maqueros is interested in safety as much as possible, and with this trick it can be increased even more if possible.
Simple and effective
What this trick allows us is destroy the FileVault storage key every time we put the Mac in sleep mode, so a new key will be generated at each boot and therefore the security will be significantly increased.
Like most OS X tricks, it is applied in the Terminal by executing a command, in this case the following:
pmset -a destroyfvkeyonstandby 1
It should be mentioned that it has two cons that from my point of view are important: it goes into Deep Sleep mode skipping the boot from RAM (which affects performance, taking longer to boot) and we will have to enter the FileVault password each time we come out of sleep to generate a new key again.
If your degree of security has to be maximum, I consider it a good trick, but for most users it doesn't make much sense to use it because FileVault itself is very secure.
Source - OS X Daily