> Beeper Mini uses another workaround for the device UUID/serial/etc. requirement.
Have you got a source on that? As far as I know, there's no workaround possible because the authentication blob is based on the UDID/serial. Put differently: without UDID/serial, there's no way of authenticating with the message servers.
Beeper keeps referring to pypush when it comes to details in their write-up[0], and pypush, in turn, clearly states[1] the need for information like serial and UDID when dealing with the albert server and IDS registration request.
As a “workaround,” they simply stuff fake serials, etc., and cross their fingers that it gets through Apple’s scoring mechanism.