Check back with this app (quickshortcutmaker) in a week or so. The developer sent me an update that worked long enough to enable the blocking mode feature. But then crashed again. I still have the feature but cannot open the app.
I know he is working on a patch to fix quick shortcuts.
Here is what I use. It's called DO NOT DISTURB by Rancho software. It works perfectly on our phones. There is a trial version and the full version I have the full version and have been using it for many months and not one issue. Give it a shot. Hope this helps.