As I installed my Ruuvi gateway, I noticed that it can forward all Bluetooth BLE packages it sees to Mqtt.
As I never got the ruuvi gateway integration working and later noticed that it uses the history-API, I stopped following that path and built an Integration to take advantage of the Mqtt-Feature of the ruuvi gateway.
If you have a Ruuvi Gateway and use MQTT, check out this Integration.
Let me know if it works or if you have any trouble setting it up.
Cheers