Hi Cam, well it is good to see another travel gun on the market. Like many things in life you only hear from people who have problems and never from those who have no problems at all. I think if fish being shot are of the usual size for consumption and are of modest dimensions then two piece shafts are not such a problem. I know if I see a fish that I am not tooled up for with my gun at the time I don't take a shot at it as I know its limitations. However not everyone has a private arsenal to select from and they may be in an area new to them, so are not sure what to expect.
I think that jam together two piece shaft that the Alemanni guy uses would be worth investigating, it is designed to stay together when moving the gun around but pulls apart when the fish runs with it. Then the shaft works like a big slip tip. It was discussed here somewhere and there is an annotated photo of it. The only downside in making it is the tie points on the shaft center join to create the cable or line hinge that holds the two pieces of shaft together and the fact that they are most likely thick shafts anyway.
I actually had some shafts built a few years ago with a similar design as his. Sort of a giant slip-tip. I'd say it works pretty well especially on bigger shafts. But, it's not exactly what you'd expect in that the connection will still break:
1. A fish will usually get several kicks of their tail before the shaft actually comes out, just taking up the slack in the shooting line. This gives a big fish plenty of time to put pressure on the connection.
2. Making #1 worse, if the slip-tip style center connection is tight enough that it functions like a solid shaft it needs to be zero-tolerance (no deflection or movement) and it doesn't "want" to come apart easily like a slip tip would. Especially when the force of the shooting line is acting perpendicular to the joint as the fish swims away. So the fish were able to get into the rocks with the whole shaft.
In these situations, the joint is only as strong as a threaded connection anyways, but with more hassle. Seeing as these situations are likely to break both shafts, I went back to threaded center connections flopper and threaded-tip shafts.
In addition to still being able to land the fish, using a center shooting line connection reduces the force the fish can apply to the joint to some extent. And, in my experience, if the fish breaks a shaft in the rocks, it was probably not far off from bending a normal shaft anyways.
That being said, we have landed some great fish on the floppers! A 95lb Grouper submerged a 30L high pressure float and the shaft didn't break or bend and the flopper was still tuned. Many yellowtail and kingie up to 58lb, cubera, grouper, a YFT, WSB, etc... but they can break them easier if they get into the rocks!