An update to an update: the APRS service SMSGTE has been replaced by one simply called SMS.
It works very similarly to the original SMSGTE, with the exception being that people have to opt-in to receive messages ahead of time. Aliases can still be created, but so far this has to be done over the APRS network itself and cannot be done via the webpage.
https://anarchistrrl.blackblogs.org/2022/03/14/aprs-idea-for-protests/
#1️⃣