At Aberdeen we have a system of codes on the strips to show what kind of pilot is flying in club aircraft.
Green-Instructor,
Amber-Qualified PPL
Red-Student solo.
This system has worked well for many years.Also the CFI asked ATC not to issue any instructions to orbit,or slow low turns.If we have to sent Cessnas around,then straight ahead until the aircraft is well up and climbing.
It's a long time since I flew,but when I regained my PPL,I had to do 2 hours of stall-spin awareness.Some of the most valuable flying going.I wonder if this poor kid had this before his solo circuits.
I have had a similar situation in an old 150,which had 40 flap.Told to go around from 200 ft,as a 757 was slow rolling.I had 40flap down,and I said to the Tower controller who was my Watch Manager that I'm happy to do a land after the departing.No he told me to go around.What a handful trying to get it to 10 flap.Then he told me to break left
The old Cessna did not have a flap detent,just a toggle and watch the flap running on the pillar.There you all the same situation that the kid faced.He perhaps forgot to put the carb heat in as well,so he would have no chance of climbing.
Lessons,
Well perhaps a start is that you could send Cessna around earlier,and give them a chance to get out the vertically.If its a late go-around then avoid any instruction that involves turning low in the go-around.