Franklin,
I happened to look in on your site and found you responded to a post of mine 3 weeks ago.
You are covering some of the same ground I work in. My work on the exceptional Jordan matrix is meant to take things to the Leech lattice and the 26-dimensional Lorentz group, which is the automorphism of the Monster group. I am not sure exactly why the gauge structure for QCD is discrete due to the large mass ot the T-quark.
The automorphism group for the Jordan exceptional algebra are the G_2 and F_4 groups. These are also the centralizers on the heterotic E_8. As such a transformation of connection terms by the g_2 holonomy generates transformations on f_4. This is in part seen in my diagram I drew up a week ago or so. In this way the curvature of the space is determined by a Skymrion abelian field term. Everything is reduced to something very simple --- indeed to something used in solid state physics.
The F_4 is connected to the symplectic group in 8 dimensions, which is reduced further to SU(4). G_2 is reduced to SU(3), which is a subgroup of SU(4). I wrote this argument up in a bit of a jarring way in the paper. Another way to see this relationship is that G_2 fixes a vector in spin(7) since spin(7)/G_3 = S^7. F_4 defines a triality of SO(8) ~SO(O), and the inclusion of G_2 in spin(8) which again has spin(7) sets the two groups in a duality of 7 vs 8, where in the Hopf fibration
S^7 - -> S^{15} - -> S^8,
There is a homotopy on how 7 spheres are tied as knots in 15 dimensions according to the Chern-Simons link invariant ∫ρ/\dρ evaluated on the sphere of dimension 2n - 1, here n = 8. So there exists a function f:S^{2n-1} S^n, such that for ω is a volume form on S^n, here n = 8 again, then f*ω is a closed form, and further since the n-th cohomology of S^{2n-1} H^n(S^{2n - },R) = 0 this form must then be exact as well f*ω = dρ, for ρ an n-1 form.
This then set the Skyrmion field theory, which naturally indicates the underlying fermionic structure. The basis elements on S^7 for the G_2 are define as
e^a = ψ^(x)γ^aψ(x)
for γ^a Dirac matrix elements of Cl_{7,1}, and gauge connections are
A_μ = ψ^(x)∂_μψ(x)
The Skyrmion field in the basic Jordan matrix in 27 dimensions is abelian, which is quantizable almost trivially. For extended Jordan matrices in 78, 133, and 248 dimensions are nonabelian, which correspond to the complex, quaternionic and octonionic J^3(O)
The G_2 and F_4 automorphisms are centralizers so gauge transformations by one group is matched by transformations of the other. This then results in an emergent Skyrmion field that is similar to a Fermi quasi-particle field. This quasi-particle field can be thought of as induced by the classical nonlinear field theory, just as knots or topological solitons in condensed matter systems are induced by an underlying system of electrons and phonons. The classical spacetime physics though emerges at low energy from this system. For higher Jordan matrix algebras with E_6 or E_8 algebra will be non-abelian, but higher groups such as the E_6 -Jordan matrix algebra things are quantizable. So curiously there is a kind of double emergence.
I have been playing with this for the last several weeks, and this appears to indicate that gravitation does not have to be quantized directly. I found this structure with the exceptional matrix model recently as a way of understanding how fermionic quasi-particles could renormalize the cosmological constant. The recent Fermi Gamma Ray observational results, with no frequency dependency on the speed of light, also suggest that ideas of violent quantum foam in spacetime are simply wrong. Gravitation does have an action in string theory
S = ∫d^nx sqrt{g}R α'R^{abcd}R_{abcd} ...
expanded around the string length for length >> than the string length. The second term is the trace of the Bel-Robinson tensor is an O(sqrt{Għ}), or order Planck length, term which is a small quantum correction to the classical term.
If you look on my blog area I have some posts on these developments, in particular detail on the g_2 algebra as a holonomy over the 7-sphere.
Cheers LC