It's surprisingly hard to find information about grid-beam online. I got this book years ago. Never really did anything with it, but it has a lot more examples: https://www.amazon.com/How-Build-Grid-Beam-Constructing/dp/0...

The problem with grid-beam is that it really only seems to make sense if you A) have lots of grid-beams in various sizes already, and B) are making, taking apart, and repurposing things frequently. Without A, making grid beams is a lot more work than just purpose-cutting your pieces, and without B, you don't really have a reason to drill all those extra holes.