You don’t need to commit Intermediate at all; as for Binaries - currenly i’m uploading everything but: *patch*, *DebugGame*. Each commit with c++ changes should be accompanied by building project in DevelopmentEditor configuration.
This way you’d have to upload 50~200mb of binaries with each c++ commit, but designers will be able to just open *.uproject file without any need for VS being installed
Note that if you using the custom in-project plugins (the ones in %project%/plugins folder), they should be setup in the same manner