@thomme
This gateway has to remember all the sensors on the mysensors network. If you would add a new sensor, you would have to detach and reattach the Z-Uno from zWave network.
I don't think you have enough memory on the Z-Uno to do such a gateway and AFAIK the sensor types supported on the Z-Uno are very limited.
My solution for integrating different iot systems is mqtt with node-red. All systems have an adapter to a generic message structure and can be connected to all the others.
I use a mix of homegear,/homematic mysensors, netatmo, zWave, owntracks, Alexa, imperihome, Sonoff...
