So here's what you do. When you order that sheet of 3/4" okoume from CLC, ask that they cut it up into 1 3/4" wide strips. They'll charge extra for that, but as long as you limit it to 16 strips total, they already have the CNC program for that (I covered that cost, you're all welcome). You should only get charged for the actual cutting. 16 strips, BTW, is enough for 24 feet of mast stock.
Next, you glue 4 strips at a time into a box that's 8 feet long (bottom), 2 1/2 inches on a side with a 1x1 hollow core. Since these are CNC cut bits, you won't need to worry about gap-filling, so good old Titebond (the waterproof version) will work just fine. Then you just use your favorite tools and technology to cut off the corners and to round what's left (top). If you make a 45-degree cut from the glue line, that takes off the corners pretty much exactly as they need to be removed. Finally, if you're really into belt and suspenders, cover it with a heavy biaxial glass sock.
To join the 8-ft sections into longer ones, trim the ends flat with a miter box and insert a 1" x 1" (actual dimensions) piece of wood in the center. Use epoxy for the joining since there may be some gaps
Okoume weighs less than pine. The 13 plies per side make it very dimensionally stable. The fact that it's BS-1088 means that there are no meaningful voids. So the result should be light, stiff and strong. I started this project as a way of making a hollow core for a carbon fiber mast, but having completed a couple of sections I can see that for small boats it'd be a good mast on its own.
Have fun all,