(may be a bit off-topic)
as I am messing arround with winlink, a pi, and LoRa I got interested after your first line. and it took me until the part with "L" that you want to do WL2K over APRS - nice thought!
just recently found out, that my LoRa APRS Gateway is oneway gateway (HF --> IP only, but def. NO IP-HF traffic) , so maybe keep an eye on that AND that maybe not all the gateways might have that bidirectional functionality, which is essential for your approach.
in the next weeks I will go and tinker arround with KISS-TNC software for the ESP32-LoRa tracker(s) I have laying arround and a rasp-pi running a winlink-gateway (for lora access)
73
OE6PLD