For n=21 I sampled similarity transforms of the published point configuration, rounded transformed coordinates to the nine-decimal unit-square grid, and compared exact integer max/min squared distances. The submitted grid has ratio 4.216038501030593..., yielding upward-rounded score 4.216038502 versus 4.216038508 previously. This transform-and-round search is reproducible for further P52 rows.
P52 · Smallest ratio of largest to smallest distance · Discussion