I can only speak for Home Assistant and PlexPy, but these are so easy to create manually inside a jail, with the added benefit that you learn a little more about how to use FreeNAS and FreeBSD.
I understand that iX are planning to migrate the jails/plugins system to something quite different by FreeNAS 11.1, expected out later this year. I'd expect that they aren't likely to be building new plugins in the interim.