I've been using the sleep timer for a while and would really love it if there were an option available for 30mins. Another great option would be to let the user set a custom time for the sleep timer. I tend to use sleep meditations on different channels and would like the TV go to sleep as soon as the meditation ends; ergo: the tv goes to sleep with me.
Thanks for sharing your idea! We'll make sure to pass this feature request over to our dev team. Stay tuned on our blog at https://www.roku.com/blog for future announcements and updates. Have a great day!