Nuts. I had a big long response with all sorts of screen prints, but I'm being prevented from including more than one image. Oh well. Here goes without the images.
I agree. Something is goofy here. I ran another set of tests:
Example 1 - Nothing enabled:
As expected no output.
Example 2 - Now, let's click that automatic polling:
As expected, no output.
HOWEVER, if I press F5 AGAIN, the output will show up!
Example 3 - DBMS Output turned on (green), no automatic polling:
As expected, output shows up, even without the automatic polling turned on.
Example 4 - enable both DBMS Output and Automatic Polling,
This works as expected. Output shows up after execution.
However, if I quit Toad and restart, the DBMS Output is off (red).
If I enable automatic polling, then exit Toad and restart, automatic polling is enabled, but no output is gathered. Running scripts after restarting follows example 2 above.
It looks like there are some inconsistencies here. Running a script two times in a row will display the second output as expected but not the first. This is independent of the DBMS Output setting.
I still think the best solution is to just allow the DBMS Output setting to persist across sessions, but now I'm a bit concerned about the strange behavior exhibited in Example 2.