We currently use Cpp11, which "is a deprecated alias for Latest" according to https://clang.llvm.org/docs/ClangFormatStyleOptions.html . I doubt this has any effect, but I think for clarity setting to c++17 make sense.
Also, remove unneeded settings:
ObjC*, as we don't write objc codePenalty, as there is currently no line limit, so this has no effectTabWidth, as we don't use tabs