Concerning Blocks on the portal frames
You don't need to block of the portal frames, in my testing and the original occurrence I locked myself without any blocks on the frames.
https://www.youtube.com/watch?v=CBriQXg7YoI Video where I do it
ok no
Concerning Blocks on the portal frames
You don't need to block of the portal frames, in my testing and the original occurrence I locked myself without any blocks on the frames.