if the save dialog closes and the application allows itself to also be closed--both without the save in progress completing fully, resulting in no save or a corrupted save and essentially a lost file and work... i would consider that a serious bug and report it as such.

OK hear me out, so I've been out drinking but I had this idea. You need to know when the save is done, right? Assuming you are on linux, you could use itnotify to alert you each time a save completes of your gimp files by ringing the console bell. Then you know you can't quit until you hear the bell.

I don't know if it would work. Maybe something like this

#!/bin/bash  

# Target directory to watch (where the gimp files are)  
WATCH_DIR="$HOME/Projects"  

echo "Listening for completed GIMP saves in $WATCH_DIR..."  

# Monitor for files closed after being written to  
inotifywait -m -r -e close_write --format '%f' "$WATCH_DIR" | while read -r FILE  
do  
    # Check if the modified file is a GIMP file (.xcf)  
    if [[ "$FILE" == *.xcf ]]; then  
        echo "Finished saving: $FILE"  
        
        # Trigger the system bell (or substitute with an 'aplay' command for a custom sound)  
        echo -e "\a" 
    fi  
done