Alternatively, you can use the Leading HTML and Training HTML properties to customize the message on the processing screen.
However, we would quickly realise that the output come appears only after the entire loop has completed and the subprocedure ended or you may a call to a msgbox or other output functions.
From the UI, it appears that the form hangs (as it process the loop) and then outputs the entire output after the delay.
a Share Point Developer, you can wrap your lengthy operations code with the SPLong Operation to display the spinning wheel processing screen whenever you are executing long duration code-block to improve the user experience.
After invoking SPLong Operation object, you can start and stop the long operation using Begin() and End() methods.
The acceptable range of delay values is 1 through 12 hours in 1 hour increments.