Comparison between ALMA data in the loopy period on 2017 Apr. 11 (blue dots) and hot spot model prediction for the inclination i = 158°, the orbital radius r_orb = 11 M, the vertical magnetic field, and the spin a_* = 0. We compare predictions of a simplified semi-analytic model (dashed red lines, Appendix B and Gelles et al. 2021) with a slow light, full radiative transfer model (continuous red line, Vos et al. 2022). A static, linearly polarized component of |𝒫_sha|=|𝒬_sha + i 𝒰_sha|=0.16 Jy and χ_sha = −37° was coherently added to the hot spot models, and the loop position angle was adjusted to match the observations.