Is this possible and why in God's name is this such a difficult question to find the answer to?
No, it's not possible. Only one Roku model ever responded to power command that was Roku 4. All Roku's released before and after do not have power. The power buttons on Roku remote are strictly TV power command buttons. Sorry.
The Roku Remote app has a power button only when controlling a Roku TV.
I turned off my theater surround and today sound is regular again. "Echo" mode kicked in mid YouTube video last night. Sitting on remote was all I did different. Crazy. Thank you for your help. I'll kudo your reply if I can figure out how to. Old Timer1
May you never find out. Thank you everyone. Answer is to turn it off and go to bed. Old Timer1