Go ahead and go to bed, and read this to help you go to sleep.
To me, spacetime works fine with Einstein's Field Equations. I think the math is beyond most layman science enthusiasts, so when I tell you the math of my wave energy density model of the ISU is daunting too, that isn't really a negative, now is it, lol.
One thing to point out is that spacetime is almost always curved, and in the ISU, for comparison, space is always flat in the context of GR, but more precisely, space never has any curvature in the wave energy density model. What makes particles and objects follow curved paths is the changing wave energy density of space relative to the presence of mass. Wave energy density tells objects how to curve along their paths.
To apply the EFEs to any given case, you determine geodesics for the motion of all known objects influencing the spacetime in that exercise. You have to know the values for a lot of variables to implement the equations, and there are exacting requirements for values of mass and motion of surrounding objects. A layman probably can't or won't want to do the math, and/or can't obtain the values and variables that equate to the stress on the spacetime that determine the curvature in the geodesics (poorly said, I'm sure).
I described the difficulty applying the EFEs, so here is the problem applying the wave energy density hypothesis. It requires a map of the value of the wave energy densities in the space surrounding our subject object. From that map data, the motion of the object will be determined by applying the process of quantum action that maintains the presence of particles and determines their relative motion, i.e., the path that the object is going to be taking. The map is generated by the out flowing gravitational wave energy component of all surrounding objects. To complicate it, those out flowing energy density components are continually expanding spherically from every object, so the map is changeing from moment to moment.
I surmise that invoking it isn't actually any different than applying the EFEs. The EFEs work fine even though the reason they work is misunderstood, according to me, and so my model fixes that and invokes the application of the EFEs, but uses a different reason for why they work.
The different reason that they work is that there are gravitational waves and light waves, coming and going through all points of space at all times, i.e, that is the source of the local wave energy density. As the local energy density of space changes, the relative velocity of light and gravity waves through that space changes with it. Consider Maxwell ...
Classically, I think it is Maxwell, in regards to light waves, the permittivity of space is the degree that the electromagnetic wave experiences the local electric field, and the permeability of space is the degree that the electromagnetic wave experiences the local magnetic field. The point is that Maxwell worked with space that has permittivity and permeability, and they govern the velocity of light through the local space, and given a vacuum, light velocity is c. Add some permittivity and permeability, and light is less than c, as in when light traverses a medium other than a vacuum; a refractive index comes into play.
Also, EM can self propagate because the oscillating light waves generate their own transverse electric and magnetic fields. That way, space can have characteristics, or can be empty, it can be just space, or it can be spacetime; light still can self propagate through it, no problem, because light is synchronized oscillations of electric and magnetic fields, perpendicular to each other and perpendicular to the direction of propagation. What changes, depending on the theoretical model, is the reason why the light takes the path it does as that light propagates.
But in the wave energy density model, light propagates spherically, and continually, from a photon along its path, no matter what its path may be, because this model is developed for wave-particles. Photons are wave particles that emit spherical light waves as they move through space; the out flowing wave energy component.
The photon in its particle state has internal composition within the particle space, including the contained energy, the inflowing component, and the out flowing component. That equates to mass in this model.
But wait, the out flowing spherical wave from the photon particle's space has no mass in the particle sense; the out flowing wave energy is the photon in its wave state. Therefore this photon can go through a single slit as a particle, while it can go through more that one slit as a spherical wave out flow, i.e., the wave state of the photon (or electron, or buckyball) goes through both slits as a wave in a two slit experiment.
The wave going through both slits will cause an interference pattern in the space between the slits and the screen, and that interference has peaks and valleys which affect the path of the photon particle that is traversing the same space after going through one or the other of the two slits, to reach the screen.
You get all this, right, lol.