Constructing an Early Universe in Relational Group Field Theory: Geometrogenesis, Finite-k Structure, and Source-Selection Boundaries

We ask how far an early universe can be constructed from relational group-field-theory (GFT) dynamics before additional state, readout, or microscopic selection becomes unavoidable. The analysis combines source-derived GFT hosts with explicitly declared reductions and diagnostics. In an interacting pseudotensorial sector, arbitrarily small but nonzero coherent condensate data can undergo exact nonlinear amplification to finite relational volume, while the exact zero state remains invariant; geometrogenesis is therefore an amplification result rather than creation from mathematical nothing. Controlled quantum sectors provide endogenous excitation and interaction-generated non-Gaussian sharpening, but neither the exact one-pair evolution nor a source-compatible two-/three-mode continuation establishes parametrically vanishing relative-volume fluctuations. Relational finite-wavenumber propagation and geometric readout can be constructed, and a subsequent same-parent audit shows that the earlier separation between finite-k relational structure and controlled interacting quantum dynamics is truncation/regime dependent: rods, a source-canonically normalized local interaction, canonical quantum evolution, a converged finite-k connected fourth cumulant, and local-volume readout coexist in one bounded source-compatible low band. A later normalization audit changes the representative finite-k cumulant but leaves this bounded co-location conclusion intact. The remaining composition burden is a full microscopic/unreduced uplift. Independently, the transfer dynamics does not select the primitive covariance, modal weights, or observable projection needed for a unique primordial spectrum. A sensitivity analysis further shows that coarse volume strongly compresses microscopic interaction-law coordinates, while richer mode/correlation readouts recover them; in the tested pre-semiclassical window this compression does not grow monotonically as volume fluctuations decrease. The resulting construction is therefore substantial but typed and incomplete: preparation, asymptotic semiclassical sharpness, microscopic uplift, and primordial state/readout selection remain distinct open boundaries.