Brent stopped over to borrow my edge rolling tool. While he was here I picked his brain about how to cutout the tank access holes. He said he basically just went really slowly and it worked out fine. I used a single Bessey clamp to clamp the rib to my drill press table.

It took about a minute to cut through (I went reaaaallllyyy slow), but the results are great.

Here's what the two inboard fuel tank ribs look like after deburring and match drilling with the access hole stiffeners.

One thing to note is that I rotated the platenut pattern 15 degrees compared to what the plans say because I was concerned about breaking into the aft tooling hole.