Just to clear some things up about the relationship between Tiberius Arms, First Strike rounds and, Perfect Circle because some people don't know or understand it.
Perfect Circle makes the FS rounds. They use the same equipment that is used to make FN303 rounds. Therefore, they stop production of FN303 rounds to make a run of FS rounds. This is why there is a small collection of colors (White for retail, Blue for default FPO, and multiple fields can in on an order for a specific color).
Tiberius Arms markets and sells the rounds (and probably packages them).
I believe that Perfect Circle developed the fin/skirt design in their work for the FN303 (core components designed and manufactured by AGD). They may have been approached by Tiberius Arms with the idea of de-weaponizing the rounds (removal of the bismuth, and secondary chamber), since, Tiberius Arms were designing the VT-MK-IV to fire FN303 rounds and, they were already in the paintball business.
Here's pic of a pepperball (also made by Perfect Circle) which shows similar pre-frag ridges:
Now for the speculation:
It's possible that Perfect Circle has other, similar hemisphere designs like those specifically shown by Scarab Arms. In which case, this may be a matter of Scarab Arms, approaching Perfect Circle with:
"Make us a round using the 'XXXX' hemisphere and the First Strike Skirt, we'll fill it manually" In which case, Perfect Circle would ship them a bunch of halves (just as we see in the picture), and Scarab would be responsible for filling and assembling them (they're able to be glued together).
Unfortunately, I can't imagine these being sold in commercial scale for the same prices that we pay for FS rounds (even their original price) with a manual assembly. If Perfect Circle is going to fill them using the FN303 equipment, then they'll get a fill port (maybe they can be filled on the rear).
Scarab Arms haven't responded to my query but, they did post up a video:
I also noticed that they are claiming longer range... Unless they make them heavier, I'm a bit skeptical as I suspect that the nipple does not make that big of a difference in range, if at all.