Thanks a lot for your answer! Do you think it’s better to use a transformed tanh (i.e. (tanh + 1)/2) instead of sigmoid for actions in the range of 0 to 1? If so, because of the stronger gradient or is there another reason?
I have switched to softplus for the activation function of the scale parameter (since this seems be commonly used) and it seems to work. Is this what you would have recommended as well?