Multiwavelength dust continuum and polarization observations arising from self-scattering have been used to investigate grain sizes in young disks. However, the likelihood of self-scattering being the polarization mechanism in embedded disks decreases for very highly optically thick disks and puts some of the size constraints from polarization on hold, particularly for the younger and more massive disks. The 1.3mm polarized emission detected toward the hot (>=400K) Class 0 disk IRAS 16293-2422 B has been attributed to self-scattering, predicting bare grain sizes between 200-2000um. We aim to investigate the effects of changing the maximum grain sizes in the resultant continuum and continuum polarization fractions from self-scattering for a hot and massive Class 0 disk extracted from numerical simulations of prestellar core collapse and compare with IRAS 16293 B observations. We compared new and archival dust continuum and polarization observations at high-resolution between 1.3 and 18mm to a set of synthetic models. We have developed a new public tool to automate this process called Synthesizer. This is an easy-to-use program to generate synthetic observations from numerical simulations. Optical depths are in the range of 130 to 2 from 1.3 to 18mm, respectively Predictions from significant grain growth populations, including a_max_=1000um are comparable to the observations from IRAS 16293 B at all observed wavelengths. The polarization fraction produced by self-scattering reaches a maximum of ~0.1% at 1.3mm for a maximum grain size of 100um, which is an order of magnitude lower than that observed toward IRAS 16293 B. From the comparison of the Stokes I fluxes, we conclude that significant grain growth could be present in the young Class 0 disk IRAS 16293 B, particularly in the inner hot region (<10au, T>300K) where refractory organics evaporate. The polarization produced by self-scattering in our model is not high enough to explain the observations at 1.3 and 7mm, and effects like dichroic extinction or polarization reversal of elongated aligned grains remain other possible but untested scenarios.