  We observationally examine cosmological models based on primordial power
spectra with quantized wavevectors. Introducing a linearly quantized power
spectrum with $k_0=3.225\times10^{-4}\mathrm{Mpc}^{-1}$ and spacing $\Delta k =
2.257 \times 10^{-4} \mathrm{Mpc}^{-1}$ provides a better fit to the Planck
2018 observations than the concordance baseline, with $\Delta \chi^2 = -8.55$.
Extending the results of Lasenby et al [1], we show that the requirement for
perturbations to remain finite beyond the future conformal boundary in a
universe containing dark matter and a cosmological constant results in a
linearly quantized primordial power spectrum. It is found that the infrared
cutoffs for this future conformal boundary quantized cosmology do not provide
cosmic microwave background power spectra compatible with observations, but
future theories may predict more observationally consistent quantized spectra.
