To be clear, there should be no difference in performance, because the only time extra work gets done is in the rare situation that the workaround is designed to fix: when an attempt is made to access a file, but the filename can't be found because it's in a different encoding (at which point the system will try alternative encodings, which might take a fraction of a second longer - but that's better than the app thinking the file doesn't exist and saying it can't find a document, etc).
So thankfully this change is implemented in a way that won't impact system performance in any way