I recently rode 2 blasters that a good friend of mine ported. Both ran FMF pipes and both had a UNI filter with the airbox. Both had identical timings and widths, but the boyesen ports we're different.
The first was aimed from higher along the intake walls, down to a steeper angle into the transfer areas. He said he only did minimal radiusing and that the port was around 7mm. He described it as a smaller 250r boyesen setup. It produced a good bit of bottom end power and had a nice wide range.
The second had boyesens that were angled more at the divider wall and were a bit larger at 8mm. He used a slightly rounded taper from the intake, but left the corners very square. With the same pipe, it made more midrange than the first and had a stronger hit when it came on the power.
Our theories for these is that the effects are based off of two things: where the port is aimed and where the charge will end up with its trajectory at different amounts of time (different rpm ranges).
I've found that a median between these two works very well. At lower rpm ranges, the charge falls short of the divider and helps the secondaries purge the cylinder. At higher rpm, it overshoots the divider and gets divided evenly when the charge flows upward.
I also like to make it easy for the AFM to flow into the boyesen ports very easily, but hard for the charge to revert.
I don't have any Blaster pics, but I do have these if my banshee templates.
These are 2 different pots on one cylinder. The boyesen ported side is an aggressive trail port and the other is a dune/light drag port.
Not everything I do is shown, only the constants that I've found. If the area looks rough or untouched, that's because I haven't researched that area.