The Graphics are excellent and it certainly looks to be a very compact engine.
Not sure about the Physics/ Applied Thermodynamics of your assertions:
The work done on the piston, by the gas pressure is = piston area x mean pressure x length of stroke.
That determines the amount of power transferred to the crankshaft.
You can not get more power out of the crankshaft than you put in the piston!
Fuel is injected before TDC partly because of the ignition delay, ignition of the fuel is not instantaneous, and by starting combustion just before TDC I always understood that this reduced the shock loading on the combustion chamber and allowed the combustion to take place at the most efficient pointy, TDC i.e. at constant volume, combustion after this point is inherently less efficient as the gas does not fully expand before exhaust and therefore potential energy is wasted.
To me it appears that there is still a tangential force on the piston because the crank throw is rotating and does not remain lined up with the centre of the piston.
If the angle of the connecting rod is changed to produce more torque at the crankshaft, then greater pressure will be required to move the piston.
The principle increase in efficiency would appear to be due to maintaining "constant volume" long enough for all the fuel to be burnt, the reason this is not done in conventional engines is because all the components have to be much heavier to support the higher pressures generated and would also have to be ceramic coated to resist the high temperatures produced.
The reason traditional diesel engines burn fuel at both Constant Volume and Constant pressure is because although burning fuel at Constant Volume is more efficient, in terms of the Carnot cycle, it cannot generate much power. Burning fuel at Constant pressure as the gas expands during the power stroke maintains the temperature and pressures at the maximum permitted by the material design and therefore enables the engine to produce worthwhile power outputs in relationship to its weight and cost.
I think your logic in suggesting that such an engine would produce 1.83 times as much power as a conventional engine and have an efficiency of over 73%, compared to the 40% efficiency of modern Marine Diesels, is flawed.
It is always better to ask a stupid question than to do a stupid thing.