I have analyzed the paper 'Is There a System Beyond the Particle?' by M. I. Sanduk. (There is a proposition that each author must review some essays. Then we'll select the best essay by comparing the merits and demerits of all essays. Please do not take offence for my review).
The essay examines the concept of particle and wave.
I believe that there are two criterions only to probe if the theory is true or false: it is the LOGIC and EXPERIMENT. Since technique can do nothing at subquantum scale, remains logic only.
Is the essay logic? I found some logical contradictions, for example:
1. 'A zero dimension particle may be considered as a black hole (where the object exists entirely within its Schwarzschild radius). It is an error. You cannot consider a zero dimension particle as a black hole because the Schwarzschild radius is always non-zero. (Because it is the RADIUS that is always nonzero). If the radius is zero, consequently it is not the radius already, it is a point. The point does not have the radius. Also, if the object exists entirely within its Schwarzschild radius, the radius cannot be zero. Thus, a zero dimension particle CANNOT be considered as a black hole
2. 'The believing in the limitation of observation means that there must be a hidden structure! The hidden structure is out of the theories that has been built already on (and for) the observed realm.'
Your conclusion is a POSTULATE, but not a logical deduction. The limitation of observation may have other causes, for example the existence of the fundamental length in space; If the spacetime has quantum (granular) structure, then the experimental access to subquantum world will be forbidden by existence of the fundamental length. You must analyze all cases before making logical conclusions; otherwise it is the arbitrary opinion, but not logic. Thus, your theory seems to be non-logic, based on arbitrary postulates.
'since there is no possibility of practical investigation, so we have no choice' We must construct at least the logical theory. Although, probably it is not possible to create a logical models inside of zero-dimensional objects in general.
My conclusion: The essay fit poorly with our essay contest because it is not new and does not contain the revolutionary ideas at the limits of physics. The most part of the ideas from essay was published already by the author in the earlier papers (2007 and 2009). I am not sure that the 'entry differs substantially from any previously published piece by the author'. It is a very speculative essay with logical contradictions;
There is a VERY low probability that this theory describes the real world. The author confirms that 'the concept of a particle is an acceptable approximation', consequently the model do not describes the true reality. It is an approximation only, a speculative model. There are no experimental proofs for this model. In my view, in the next years may appear other new theories explaining the concept of particle and wave. FQXi can award every year new theories of concept of particles with the same success. It is the subquantum world that is outside of logic and experiment.
P.S. I'm sure that the key for the concept of particle lies in the area of gravitation and space-time. If you want to explain the concept of particle, you must explain first why particle have mass, inertia and lifetime.