I have a windows machine that I keep powered down most of the time, but its got wake on lan enabled in bios. until today I have always logged into my router interface remotely to wake the pc, but I have found this awesome container that makes things so much easier and prettier.
https://github.com/Misterbabou/gptwol
GPTWOL gives a nice pretty web ui, it checks whether a device is on every 30 seconds, and lets you send WOL packets really easily.
I recommend installing it as a custom app on your truenas instance!