HST spectrum (black line), Sonora Diamondback best-fit spectrum (blue line), and petitRADTRANS retrieval spectrum (red line) is in the upper panel for each plot. The bottom panels shows the spectral variability amplitude for each object (green, blue, or red lines). The cloud and spot driven spectral variability models are plotted in black and gold, respectively. For both 2M1721+33 and 2M1906+40, the cloud-driven and magnetic spot-driven models both provide adequate fits to the data. For both observations of 2M0036+18, there is a slightly more favourable χ²/ν value for the spot model over the cloud model.