iOS sideloading error -80046, and how I solved it in Apparition

Since 22 October, free-account sideloading tools fail with -80046 right after the password. Apple stopped issuing the developer token to sign-ins that claim to come from an Android phone. Claiming a Mac on that one token request works. On 29 October a separate 403 turned out to be a firewall rule on the Content-Type header, fixed by sending text/xml.