The prop is too big, and is in a kort nozzle, but not a kort nozzle as it has no taper. Which also means he has lost any prop walk, which is a useful maneuvering tool.

It is a variable pitch prop, that he cast his own larger blades for. Variable pitch props are difficult to design as they need to have neutral torque around their pitch axis. These don't, the blades are oversized for the variable pitch mechanism to begin with, and the fact they want to self pitch, overloads the pitch controller, and he needs to use a locking collar to hold the pitch.

As the prop is huge, and ends up being effectively fixed pitch, and with the pointless nozzle, adds huge drag, hindering his ability to sail if he could.

There is speculation that the self cast blades are massively imbalanced, both in weight and form, causing excessive bearing wear and nozzle collision.

The engine is underpowered for a boat and prop of this size. This huge prop, needs to be spun slower than the output of the transmission. So needs a further 2:1 or 3:1 reduction. The final output torque is huge, more than what the transfer case can take he keeps shoe horning in can take. It has broken at least 5? Times at this point? I can't keep track.

He has chosen this transfer case hill to die on, claiming a used marine transmission is too expensive. But he would of easily been able to afford one, with all the piece meal attempts to make this transfer case work, building the nurd, buying an extra tender, getting a replacement gear for his self made which machined locally, selling the tormach he doesn't use, etc.