VSCO has camera specific profiles for many camera models including 5D Mark III. Each camera profile corresponds a preset, so for example a preset for Kodak Portra 160 for Canon would trigger a change in develop module including a change of the camera profile - as long that camera's specific profile is installed in CameraRaw folder. I have installed profiles for my most used cameras, present and past. I shoot only Canon and have second shooters who use Nikon. I made sure to install profiles for each of those specific cameras.
I have just launched a LR catalog from a shoot a month ago and it recognizes the profiles. That shoot was done with 1D Mark IV, so would need to guess that 5DMkIII profiles somehow don't load correctly, but I am not sure what to do because they are installed in the same location and the same way as profiles for 1DMkIV. Besides, these 5DmkIII profiles used to work before, but they don't work now, and I haven't changed anything with the exception of updating Lightroom about 8 days ago.