We have kids of 3 and 5. Put them in the water from day 1.
The 3 year old started swimming without a floating device this Summer. And she can probably last 1 minute.
A pool fo that size and without shallow areas would have been a danger for the kids for the next 4 or more years.
I would have not bought the house in the 1st place.... everything else is perfect apart from that huge hole in the back yard
Now I think this solution is the best because you retain the pool for the future.
Last comment about the craftmanship.... incredible.