That thread containing the dev client was shut down because clientside loading is no longer supported. They cannot account for the bugs and client breaks you may encounter. We are, however, permitted to patch our own exe to allow testing, we just won't receive any help from the staff team in doing so. it's understandable. If you understand the risks involved and are willing to take them, thus losing any help from the staff team with errors, bugs, or glitches you may encounter, send me a dm on Discord and I can help you do this. Just ensure you're aware that you will not receive any support whatsoever.
EDIT: It's been a topic beaten to death, but also keep in mind that this only works until we update to 7.3. then it's gone for good.