My main realization was that Bluetooth LE is mostly different from "normal" ("basic rate", BR) Bluetooth.

Normal Bluetooth is mostly exposed to the OS as a socket/serial connection, with all the protocol around it, and you can mostly use any of the serial TTY modules like SerialPort.

Bluetooth LE puts a lot more work on the "master", by doing away with the "connection" model and expects the main machine to poll/poke addresses on the BLE device instead to transfer data.

In my investigations, I did not find readymade Perl modules, but in theory using DBus directly to talk to Bluetooth could work (if your OS uses DBus).

BLE terminology, topology

BLE primer