I made a version of the tri-bahtinov mask to help me dial in the collimation on my Mak-Newt. I went with three Bahtinov masks but the straight and angled peices on opposite sides of the mask. Same principle just easier for me to draw up in CAD. I tuned the image using Maskulator and it worked wonderfully. It's really remarkable how perfectly Maskulator's simulations come out. What it predicted was exactly, I mean exactly what I saw in the eyepiece.
I previously have been using software to dial in my final collimation and that takes a long time. The tri-Baht is much much faster and really quite an amazing tool when you really want to nail your collimation. Two huge thumbs up!
That looks like an interesting design. How did you come up with that idea? It looks like it would be easier to cut out than the other patterns.