@Aegewsh
Regarding the evolution of #APRS, I agree that the AX.25 over-the-air protocol impose constraints on both AfskAPRS and LoRaAPRS. And, yes, this involves digipeating as you point out.

However, those constraints don't impose anything in the APRS-IS network core. iGate are part of the APRS-IS network. SSIDs on APRS-IS are just a dash and a string appended to a callsign — they don't have to be numeric at all, let alone 0–15

@Aegewsh
I was on packet radio using @AX25 on a TAPR TNC and an ADDS Video Terminal in the early 1980's before Bob Bruninga came along. #APRS created many one-way devices such as the tracker that I had for a long time. It just transmitted. Many of the devices that came along were incompaticle with the very intent of the AX.25 protocol.

Yes, I used to be very active on many LoRa projects, incuding Peter Buchegger's telegram group in German.

@Aegewsh #LoRaAPRS #APRS

I fully agree with you that the AX.25 / APRS (Bob Bruninga's implentation of AS.25) standard only supports SSIDs numbered 0-15. It's a radio protocol.

However, an iGate is an internet device. It never hears the tracker's RF transmission. It's not the destination of packets.

On APRS.fi / internet side: Anything goes — higher SSIDs (or even letters) are fully supported and displayed because it's all text over the 'net, not constrained by the ancient 4-bit field.