Which online services were you able to find that allows changing class type?

contingencies · on Aug 10, 2021

I believe I have used some in the past. Possibly via http://fortytwo.com in an earlier incarnation (way before twilio existed). You can ask around for 'raw SMS PDU' support. You can safely claim it is for 'custom character set' (non UCS-2) usage. This is reasonable to use for developing markets where local pre-unicode character sets allow greater information density in a single message.

IIRC you can grab inbound Flash SMS from at least some devices using AT commands the same way you'd grab regular SMS. They won't show up in native messaging apps, however.

mcsniff · on Aug 10, 2021

Yeah, unfortunately I haven't been able to find any current providers that allow sending raw PDU packets. I'd love to get away from using dedicated hardware + local SIM card.