The issue I am concerned with is the 30+ degree slope into the skimmer opening. They used Mortar to build up the pool shell to match the bottom of the waterline tile. I am adding new photo to better show the issue. Wider shot to show more perspective.If I understand you correctly, yes the skimmer will work 1” above the normal level. Where you run into problems is when the water level is too low and a chance of sucking air into the plumbing.