Can I use alternative ML models (NN) instead of the decision tree?

No, this is not possible on this product, we laverage just on a decision tree algorithm here which can't be change. Howvever, we have a new device embedding the ISPU feature where you can bring your algorithms directly in the core of the MEMS Sensor. Check on our webpage for ISPU, there are two products, the ISM330IS and the LSM6DSO16IS which are already availble and you can use for your purpose