There is no way you can get a spade rudder as strong without a skeg, as you can with one. A rudder behind a skeg has a much higher stall angle. Even a partial skeg with a balanced bottom is much stronger. Puts the bending load on the rudder blade, rather than on a shaft with very highly loaded bearings.
You really need to stop saying stuff like this. You are a professional yacht designer! When you write stuff like this you might give folks the idea that you don't understand basic engineering.
Take your statement "there is no way you can get a spade rudder as strong without a skeg."
Of course there is, it just takes better engineering. Both a skeg and a post hung rudder, and even the transom hung rudder in the 'my version' design are simple cantilevers. Each have a maximum embedment equal to the length between the hull and the deck to develop enough moment to resist the forces acting on them. And each develop a combinnation of lateral and longitudinal forces which relates to their physical shape, and what they encounter enroute. The forces that they have to resist are quantifiable and simply need to be engineered for.
Is it harder to engineer a rotating cantilever than a fixed one? Certainly! But does that mean there is no way to do it? No....in reality for any given skeg hung rudder design it is possible to analyze how much force that skeg and rudder can withstand, and then if so desired, engineer a rudder post, and bearings to withstand those identical forces. It's just not that hard if you understand basic engineering.
Similarly your statement that a rudder behind a skeg has a much higher stall angle, suggests that you stopped learning about yacht design at some point in the 1970's when that was still thought to be the case. Since then there is a much better understanding of how rudders in non-compressible fluids behave and designers can shape rudders such that a spade rudder does not have to be any more prone to stalling than a rudder behind a skeg. But beyond that, there is also an understanding that sailboat rudders don't usually stall in the same aerodynamic sense as this term is generally used.
What a sailboat rudder actually does at least most of the time that people think it stalled is develop so much low pressure that is sucks air down the blade, in doing so creates a fluid that is a mix of air bubbles and water, making the water a less effective media to generate lift and thereby reducing the ability of the rudder to create the needed turning force.
For this reason as rudders have gone to smaller area, and higher aspect plan forms, thereby generating greater negative forces, designers have pushed them further forwards under the hull, and away from the free surface.
A fairer criticism of the outboard rudder shown on the My Version design is that it would be more prone to sucking air since it is at the free surface. For that reason, I purposely drew a larger rudder than I would have had to if the rudder was.well beneath the hull, and took the penalty of greater drag in order to preserve some pragmatic solutions to other concerns explained in other posts of mine above. The greater area reduces the square unit pressure on the foil and therefore reduce the force needed to cause the water to aerate.