Something I'm becoming more sure about is that I do not like the curved spacetime of general relativity, because, as Mach might have put it, bent space, just like absolute space, is a "thought thing" that one cannot directly observe. I would much rather base a theory, and I have based MiHsC, on things that can be better observed. For example: masses, distances, accelerations (more robust than velocities since they are independent of the reference frame) and also boundaries like the Hubble-scale, which can be seen in the sense that they are a boundary to what can be seen.
The curved spacetime of general relativity is the ultimate product of the Newtonian or differential toolbox, the idea of a continuous field. In my opinion it has not worked because nature is full of abrupt event horizons, and I think the way forward is going to be based on observables like masses, accelerations and boundaries.