Scratch 3.0 allows users to create custom blocks that can run entire scripts at once, only stopping to refresh the screen once the script is finished. This feature is called “run without screen refresh” and is an optional feature.

Currently, once a block is created, there is no real visible way to tell that a block has this feature enabled without running or editing it.
I'd like to propose some sort of icon or other indication for custom blocks to make it absolutely clear from a quick glance that they will run without screen refresh.
Here's a quick mockup I've made:



The “no refresh” block has “run without screen refresh” enabled, and therefore displays an icon (a clockwise arrow with a line through it) to indicate this.
The “refresh” block has “run without screen refresh” disabled, and therefore does not display any such icon.

Support. Many new scratchers' projects are broken due to not checking a block as run without screen refresh. This could prevent at least some of these eventualities.

There should be some indicator to differentiate between screen refresh custom blocks and non-screen refresh custom blocks. Personally, I'd prefer going with this option, though I know that there's also a suggestion to give custom blocks a different color based on their screen refresh status.

Duplicate, though I like your mock-ups so I think that you should post them in that thread