. . . . it will then ask for the image that you want. . . . .
This is very inconsistent for me - the file dialog does not open for the first waypoint set, subsequent waypoints are OK one change only, trying to change the image again fails and also leaves an image not attached to a waypoint.
You have certainly given me a starting point which I never had. Working on it this morning (my 80th birthday). I am sure this is the way to go. You, and yours, stay safe...captjack...