I've reuploaded the standard version of 0.3.4 so it will (hopefully) be listed as the latest. I don't use the itch client and don't know many people who do, so I apologize for the inconvenience.
Yep, that worked. I did have to uninstall and reinstall since my old installation was now completely defunct, but it now registers them as separate downloads.
BTW, the problem wasn't that 3.4 wasn't registering as the latest version, but that Content Creator was registering as an update from 3.4 rather than being a separate entity. But that's fixed now.