This may be a limitation of PMS at the moment but I would like to be able to view movies by studio. I successfully changed MovieSectionTopLevel.xml to link to a list of studios, but selecting a studio results in "unavailable". I tried manually browsing to IP/library/sections/37/studio and that works, but IP/library/sections/37/studio/Studio%20Key (using a key found in the studio XML result) does not. I'm assuming therefore it's not available to PlexConnect?
Unfortunately the “studio” endpoint in the PMS library does not work 
As you found out /library/sections/37/studio will list the studios but adding the key to the end results in an empty xml. Once this gets fixed in PMS I’ll add it to PlexConnect 
