If I had seen this before I could have chimed in. I did like 79 while planning my arm project and looked at the banshee hubs for a comparison.
The banshee hubs are similar (as pictured) but there are some differences, the upper ball joint mount is different (as mentioned) but also ~ 1/2" shorter than the blaster upper ball joint mount. I'm not sure if that's because yamaha designed in room for the pinch bolt upper joint or what. The 1/2" shouldn't make much difference in the final calculations. If you make a set of arms, you'll have to add 1/32" to the length of the upper to compensate (or something silly like that).
The tie rod (pitman arm? on a quad) mounting location looks WAY different on the banshee but if you hold them up against each other, you'll notice they're made different but the mounting hole is backwards too. The blaster tie rod goes on top of the spindle arm, the banshee tie rod goes under the spindle arm. Mounted, they actually pass through nearly the same plane (for bumpsteer purposes) so the changes should be neglegible. The banshee tie rod mounting point is a little farther out (away from the center line of the ball joints) which will decrease the turning radius some but also decrease the turning effort some too. It's a trade-off... Although, 79, your second picture is deceiving. There is webbing on the back of the banshee hub which is sitting on the 2"x4" and the blaster hub doesn't have that webbing so it's sitting flat. The result is the tie rod mounting locations look WILDLY different when they're not quite that different. The third picture is more like the difference, you can see the tie rod mounting locations in the background. The banshee tie rod mounting location is ~1/2" farther away from the ball joint centers than the blaster.
In summation, bunches of aftermarket arm manufacturers make arms to fit the banshee hubs to the blaster. Not only is it possible and feasible but works well too. If you decide to swap over to the darkside, take LOTS of pictures. It's always nice to see what someone else did too!