nah that's how I do it and the only way you can do it.
my account = primary account on their ps4
they then use their own account as a sub account on their ps4
my main account on my ps4 is my account but i never set it to be the primary ps4 obviously. only my account has access to psn plus and the games whereas on their console they can access my psn plus to play online and as well as all my games on any account on their ps4.
i then send them games from the pc store as i have put a pin on my account on their ps4 so they cannot access my account and therefore my store.
for instance today i asked them if they wanted the final fantasy beta, they did so i sent it to their ps4 from the pc, they got it instantly.