Lora and Espruino

Why do you think you need the Arduino IDE for RN2483? I have Espruino devices using it here without an Arduino in sight. As the RN2483 page suggests, you connect 5 wires between the two boards, and that's it - LoRa.

Also, why would someone choose the Espruino WiFi when they are connecting via LoRa?

Espruino WiFi can be a WiFi access point, so maybe they are trying to aggregate data from several WiFi devices in a location that doesn't have internet access and send them over LoRa. Also, the WiFi board is a bit faster with a bit more memory.

All that page is saying is that since the WiFi and Pico boards share basically the same Pinout you can use either of them with that adaptor PCB.

Are you ever in London for say, IoT meetups?

I am very occasionally. I have nothing planned at the moment though.