I made this to test forcing scratch to update the screen while in a run-without-screen-refresh block. This is achieved with an empty say block. Try removing the say block and try removing the condition from the say block. Note that the Draw block always starts with setting the costume to Scratch and ends with setting it to a dot. If the screen updates only at the end of execution, Scratch will never be visible. The fact that Scratch is visible shows that the screen is being refreshed in the middle of the block. Previously wait(0) also worked, but a past update broke this functionality. wait(0.001) also works but causes large amounts of lag.