Moon with Auto Focus (AF) Point Selection: Manual Selection vs. Auto Selection

My Canon T5i has 9 point autofocus, and similar to when I was shooting with the Rebel XT, I figured the camera would select the center point when focusing on a single object in a black field - such as a bright star of the moon. After shooting several moon stacks with slight fuzzyness, I determined using the auto focus point auto selection isn't as crisp as using the manual selection with the center point.

Comparison between Auto AF Point Selection and Manual AF Point Selection in single frame

This seems to resolve the problem I was having with my T5i moon photos being less than crisp around the edges even in decent viewing conditions.

The result of a stack of 39 images in Registax, with some modest High Pass in Photoshop...

Stack of 39 frames in Registax, each at ISO 100, f/11, 1/50 sec, 300mm

That's more like it! Now I just need to replicate this for each phase of the moon! Kidding... but I'll probably get around to it eventually anyway.