One of the details of MiHsC that I have not as yet been able to model is subtle, but fairly unique, and so it might make a good test. MiHsC assumes that inertia is caused by Unruh radiation (a kind of wave in all the fields you can think of, including the electromagnetic and particle fields). This Unruh radiation is not made of just one wavelength but a broad Planck spectrum of radiation with a peak wavelength of ~8c^2/a, where a is the acceleration. MiHsC assumes that from this spectrum only wavelengths that fit exactly into the Hubble scale are allowed: a Hubble-scale Casimir effect (MiHsC = Modified inertia by a Hubble-scale Casimir effect). So far I have just assumed that this subsampling of this spectrum produces a 'linear' decrease in energy as acceleration reduces and less of the spectrum is allowed or sampled. I showed, in the paper below, that this 'linear-MiHsC' is a good approximation, but I haven't yet properly considered the smaller effect of the shape of the spectrum and where in the spectrum the allowed wavelengths are.
I discussed this a little in the discussion of the paper below. It means that when an object has such an acceleration that the peak wavelength of the Unruh spectrum it sees fits exactly into the Hubble scale (a 'resonant' one) then its inertia will be at a maximum according to MiHsC, and when the peak wavelength of Unruh radiation that it sees does not fit exactly into the Hubble scale then its inertia will be slightly less. This will not matter so much for high acceleration objects because so many of the wavelengths in the spectrum will be allowed so that wavelengths close to the peak wavelength will exist, and linear MiHsC will be a good approximation. For example, for Pluto or another object out at about 40 AU from the Sun there are still 4000 wavelengths within the Unruh spectrum allowed by MiHsC.
However, for extremely low accelerations only a few wavelengths will be allowed from the spectrum so it is not guaranteed that the sampled Unruh wavelengths will be close to the peak of the spectrum, so the difference in the inertial mass between an object with a 'resonant' acceleration and a non-resonant one will be larger: linear MiHsC will be inaccurate. Therefore as you go out from the centre of a rotating system like a galaxy, and sample lower and lower orbital accelerations, at certain radii this subtlety of MiHsC predicts that the inertial mass should be slightly greater so the extra centrifugal force will push matter outwards, and at other radii the inertial mass is predicted to be lower so the centripetal gravitational attraction produces more inwards acceleration. I have not modelled exactly what this would mean for the density distribution in a galaxy since this needs a full galaxy model, but this process should produce concentric patterns at larger galactic radii. To get acceleration low enough to see this in the Solar system you'd need to go out to about 1000 AU and be careful that you're not seeing other effects (eg: the orbital resonance that might produce the Titius-Bode law). Anyway, this is another way to look for MiHsC and the more ways the better.
McCulloch, M.E., 2007. Modelling the Pioneer anomaly as modified inertia. MNRAS, 376, 338-342. Link