Tried a different OPM parallax mod. This one made by Lithium-7.
It seems so far like any parallax mod that changes OPM(and presumably also MPE) conflicts with the most recent update.
Haven't tried others yet but I haven't gotten any infinite loading with Parallax, Parallax Stock Textures, and Parallax Scatter Textures so I'm not sure if Parallax itself is the issue.
Edit: Forgot Kcalbeloh had integrated parallax stuff. It doesn't trigger the loading glitch either so its probably something to do with the parallax mods for OPM? Not sure exactly what but it doesn't seem to be specifically changes to MPE(could be wrong though?) since with Lithium-7's mod I only installed the OPM additions. Not sure if Onesaltypringle's makes any changes to MPE however.